Electronic component

ABSTRACT

The invention is to provide an electronic component which can obtain the capacitance value of a capacitor element highly precisely. An electronic component has a lower conductor (first conductor) which is formed on a planarized layer of a substrate, a dielectric film which is formed on the lower conductor, and an upper conductor (second conductor) which is formed on the dielectric film and thinner than the lower conductor. A capacitor element (capacitative element) is configured of the lower conductor, the dielectric film and the upper conductor.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electronic component having acapacitor element.

2. Description of the Related Art

On an internal circuit of electronic appliances such as a personalcomputer and a cellular telephone, various surface mount electroniccomponents are mounted. For the surface mount electronic component, thinfilm electronic components are known that are formed using thin filmformation technique.

For thin film electronic components, a thin film capacitor, a thin filminductor, a thin film LC composite component, a thin film lumpedconstant device, a thin film distributed constant device and a thin filmmultilayer composite component are named. In addition, for compositecomponents having a capacitor, a low pass filter (LPF), a high passfilter (HPF), a bandpass filter (BPF) which passes only signals in apredetermined frequency range and attenuates signals in the otherfrequency ranges, a trap filter which removes signals in a predeterminedfrequency range, and so on are named. In addition, for the otherelectronic components that combine them, a diplexer, a duplexer, anantenna switch module, an RF module and so on are named.

For electronic components for use in frequencies of 500 MHz or above,particularly for high frequencies of microwave frequency bands (GHzbands), it is demanded to realize reductions in size, thickness andcosts. With regard to the thin film electronic components having acapacitor element, reductions in the electrode area and the number oflayers of dielectric films of the capacitor element greatly affectreductions in size, thickness, and costs and the realization of highfrequency of the electronic component. In the capacitor element for usein high frequencies, a dielectric film of a high dielectric material isused, or the film thickness of the dielectric film is decreased tointend the reduction in the electrode area of the capacitor element andto intend reductions in size, thickness, and costs and the realizationof high capacitance. Moreover, the dielectric film is multilayered tointend the realization of high capacitance of the capacitor element.

FIGS. 35A and 35B show the schematic configuration of a conventionalthin film capacitor element 411. FIG. 35A shows a plan view depictingthe capacitor element 411, and FIG. 35B shows a diagram depicting across section cut at line A-A shown in FIG. 35A. As shown in FIGS. 35Aand 35B, the capacitor element 411 has a lower conductor 421 which isformed on a substrate 51, a dielectric film 431 which is formed on thelower conductor 421, and an upper conductor 423 which is formed on thedielectric film 431. Portions of the lower conductor 421 and the upperconductor 423 function as the electrodes of the capacitor element 411.

The capacitance value of the capacitor element 411 is defined by an area(electrode area) that the upper conductor 423 and the lower conductor421 are faced to each other, and a film thickness d and the dielectricconstant of the dielectric film 431. The electrode area that is onefactor defining the capacitance value of the capacitor element 411 isdefined by an area l₁×l₂ of the dielectric film 431, the area issandwiched between the lower conductor 421 and the upper conductor 423.

The dielectric film 431 covers the top and the end part of the lowerconductor 421. The film thickness of the dielectric film 431 tends to bethinner at the end part of the lower conductor 421 (in FIG. 35B, thefilm thickness f) than the top of the lower conductor 421 (in FIG. 35B,the film thickness d). When the dielectric film 431 is formed in a thinfilm, at the end part of the lower conductor 421, the dielectric film431 might not be formed on the lower conductor 421. Thus, the insulatingproperties between the lower conductor 421 and the upper conductor 423are not sufficiently obtained at the end part of the lower conductor421, and short circuit defects tend to occur. Therefore, a problemarises that the breakdown limit of the withstand voltage of thecapacitor element 411 drops to cause the unstable quality betweenproducts against electric power. Short circuit defects and a reductionin the breakdown limit of the withstand voltage tend to occur when thefilm thickness d of the dielectric film 431 is thinner than thethickness of the lower conductor 421 and the upper conductor 423, andwhen the end part shape of the lower conductor 421 is in a reversetaper.

Therefore, in the capacitor element 411, a material of high insulatingproperties is used for the dielectric film 431, or the film thickness dof the dielectric film 431 is thickened to intend the improvement ofdielectric voltage. However, when the film thickness d of the dielectricfilm 431 is thickened, it is necessary to increase the electrode areal₁×l₂ of the capacitor element 411 in order to obtain high capacitance,causing another problem that it is difficult to reduce the size of theelectronic component having the capacitor element 411.

In addition, the accuracy of the capacitance value of the capacitorelement 411 is affected by the accuracy of the relative positionsbetween the lower conductor 421 and the upper conductor 423, theaccuracy of the shape of the lower conductor 421 or the upper conductor423, the accuracy of the film thickness and the dielectric constant ofthe dielectric film 431, the surface roughness of the lower conductor421 and the upper conductor 423, etc.

However, the capacitor element 411 has a problem that when it is reducedin size, the accuracy of the relative positions between the lowerconductor 421 and the upper conductor 423 drops, and it is difficult toobtain the capacitance value highly accurately. Moreover, in order toconsider equivalent series resistance (ESR) and parasitic inductance, inthe cases in which the set film thickness of the lower conductor 421 isthick, and in which the wiring length of the lower conductor 421 islong, the capacitance value of the capacitance formed between the endpart of the lower conductor 421 and the upper conductor 423 becomeslarge, and the unevenness of the film thickness f of the dielectric film431 covering the end part of the lower conductor 421 adversely affects adesired capacitance value.

In addition, in the electronic component having the capacitor, thecircuit layout is adjusted so that the distance between the conductor ofthe capacitor element 411 and the terminal is reduced and a leadconductor that connects the capacitor element 411 to the circuit deviceadjacent to the capacitor element 411 is shortened, whereby it isintended to reduce parasitic inductance and stray capacitance.

However, since a part of the lead conductor contacts with the dielectricfilm 431, the capacitance value of the capacitor element 411 isdifferent from the design value when the positions of forming the lowerconductor 421 and the upper conductor 423 are shifted. In order toreduce a shift of the capacitance value of the capacitor from the designvalue, for example, the width of the lead conductor is formed narrow.Since the width of the lead conductor is formed narrow to increaseparasitic inductance, problems arise that the high frequencycharacteristics of the electronic component are degraded, and that thetransmission loss becomes large.

FIG. 36 shows a cross section depicting a thin film capacitor element1011 disclosed in Patent Reference 1. As shown in FIG. 36, the thin filmcapacitor element 1011 has a lower electrode 1021 and a dielectric layer1031 in turn laminated on a substrate 51 in which the rim part of thedielectric layer 1031 is covered with an insulating layer 1033 having anaperture 1033 a, and an upper electrode 1023 formed on the insulatinglayer 1033 is laminated on the dielectric layer 1031 in the aperture1033 a. With this configuration, since the insulating layer 1033covering the rim part of the dielectric layer 1031 surely insulates thelower electrode 1021 from the upper electrode 1023, drops andfluctuations in the breakdown voltage caused by the coverage defect ofthe dielectric layer 1031 can be surely prevented. In addition, sincethe aperture of the insulating layer 1033 defines the capacitance valueof the capacitor, the variations in the capacitance value can bedecreased regardless of the accuracy of the size and alignment of thelower electrode 1021 with the upper electrode 1023.

However, in the thin film capacitor element 1011 disclosed in PatentReference 1, since the upper electrode 1023 is also formed in the samelayer as the lower electrode 1021 and faced thereto through theinsulating layer 1033, parasitic capacitance (stray capacitance) occursbetween the side part of the lower electrode 1021 and the upperelectrode 1023. Since the insulating layer 1033 becomes thinner as thethin film capacitor element 1011 is reduced in size, the ratio of theparasitic capacitance to the capacitance value of the thin filmcapacitor element 1011 becomes large. In addition, since the insulatinglayer 1033 has a shape that protrudes toward the surface of thesubstrate 51, it is difficult to form the thin film capacitor element1011 in the layered structure. Moreover, since the circuit device suchas an inductor element cannot be formed near the thin film capacitorelement 1011, it is difficult to intend to reduce the size of acomposite component having a plurality of circuit devices.

A capacitor element which solves the problems described above isproposed by the inventors (Japanese Patent Application No. 2005-333108).FIG. 37 shows a cross section depicting a capacitor element 611 proposedby the inventors. The capacitor element 611 has a lower conductor 21which is formed on a substrate 51, a dielectric film 31 which is formedto cover the substrate 51 and the lower conductor 21, an insulating film33 which is formed on the dielectric film 31, and an upper conductor 623which is formed over an opening 33 b that is formed in the insulatingfilm 33 on the lower conductor 21 and which configures a capacitorelement 611 with the lower conductor 21 and the dielectric film 31. Theopening 33 b has such a square shape that for example, the length of oneside is l when the substrate 51 is seen in the normal direction of thesubstrate surface. The upper conductor 623 has a column shaped conductorpart which is formed in the opening 33 b, and a lead conductor partwhich is formed on the insulating film 33 to connect the upper conductor623 to the other circuit devices such as an inductor element or anexternal electrode (not shown).

The upper conductor 623 is extended over from the opening 33 b to theinsulating film 33, which is not formed in the same layer as the lowerconductor 21. Thus, even though the film thickness of the dielectricfilm 31 is thin at the end part of the lower conductor 21 or it is notformed at the end part thereof, the lower conductor 21 is not shortcircuited with the upper conductor 623. Therefore, the breakdown limitof the withstand voltage value and the insulating properties of thecapacitor element 611 are improved, and the quality variations inelectronic components having the fabricated capacitor element 611 aresuppressed.

In addition, in the capacitor element 611, since the area (the openingdiameter) 12 of the opening 33 b defines the electrode area of thecapacitor element 611, the capacitance value is not varied even thoughthe position of forming the upper conductor 623 is shifted. Therefore,the capacitance value of the capacitor element 611 can be obtainedhighly accurately. In addition, when the insulating film 33 isthickened, the parasitic inductance and the stray capacitance generatedbetween the lead conductors of the upper conductor 623 and the lowerconductor 21 are decreased. Therefore, the capacitance value of thecapacitor element 11 can be made more accurately.

In addition, since it is unnecessary to thicken the film thickness ofthe dielectric film 31 in order to prevent a short circuit between thelower conductor 21 and the upper conductor 623, the film thickness ofthe dielectric film 31 can be made one tenth of the film thicknessbefore (2 to 3 (μm)) or below, and the capacitor element 611 of highcapacitance can be obtained. In addition, since the sufficientcapacitance can be obtained even though the size of the electrode areaof the capacitor element 611 is reduced, a reduction in size of theelectronic component having the capacitor element 611 can be realized.

In addition, different from the thin film capacitor element 1011disclosed in Patent Reference 1, since the capacitor element 611 has thestructure in which the upper conductor 623 is not faced to the sidesurface of the lower conductor 21, the parasitic capacitance generatedbetween the side part of the lower conductor 21 and the upper conductor623 is little varied even though the electronic component 1 is reducedin size. In addition, the insulating film 33 is thickened to a few μm,whereby the parasitic capacitance can be suppressed.

Moreover, different from the thin film capacitor element 1011 disclosedin Patent Reference 1, in the capacitor element 611, since theinsulating layer 1033 in a protruded shape toward the substrate surfaceis not formed and the insulating film 33 is formed almost throughout thesurface of the substrate 51, the electronic component having thecapacitor element 611 can be easily formed in a super multilayer form.Moreover, since the protruded insulating layer 1033 is not formed in therim part of the capacitor element 11, the other circuit devices such asan inductor element can be formed near the capacitor element 11.Accordingly, a reduction in size of the electronic component having thecapacitor element 611 can be realized.

However, the capacitor element 611 has a problem that when it is furtherreduced in size where the length 1 of one side of the opening 33 b isl=5 (μm), for example, the electrode area cannot be formed highlyprecisely, and the capacitance value cannot be obtained highlyaccurately.

For example, the insulating film 33 is formed of a photosensitive resin(photoresist). When a photosensitive resin is used for a material forthe insulating film 33, the insulating film 33 is formed and then theinsulating film 33 is exposed and developed to form the opening 33 b. Inaddition, after the opening 33 b is formed, the insulating film 33 ispost baked to remove a photosensitive group and an organic solvent inthe insulating film 33. Accordingly, the insulating film 33 excellent inenvironmental resistance can be formed.

Post bake causes the insulating film 33 to cure and shrink. Theinsulating film 33 is contracted by cure and shrinkage, and the area ofthe opening 33 b is increased. However, an increase in the area of theopening 33 b caused by cure and shrinkage is varied for every product.Thus, variations occur in the area of the upper conductor 623 formed inthe opening 33 b. On the other hand, in order to suppress the parasiticcapacitance generated between the side part of the lower conductor 21and the upper conductor 623, it is necessary to thicken the insulatingfilm 33 to a few μm. The amount of cure and shrinkage of the insulatingfilm 33 is more increased as the insulating film 33 is thicker. Inaddition, the area of the opening 33 b is more decreased as thecapacitor element 611 is more reduced in size. Therefore, when thecapacitor element 611 is reduced in size, the variations in the area ofthe opening 33 b caused by cure and shrinkage greatly affect theaccuracy of the area of the opening 33 b. Thus, the capacitor element611 has problems that when it is reduced in size, the electrode areacannot be formed highly precisely and the capacitance value cannot beobtained highly accurately.

As the properties of the material for forming the insulating film 33which affects the accuracy of the capacitance value of the capacitorelement 611, there are hygroscopic properties and workability inaddition to cure and shrinkage. In addition, methods of forming theopening 33 b, such as photolithography, laser and plasma, also affectthe accuracy of the capacitance value of the capacitor element 611. Thesame problem arises when photosensitive polyimides, photosensitive epoxyresins and photosensitive benzcyclobutene are used for the material offorming the insulating film 33.

It is possible to use inorganic materials for the material of formingthe insulating film 33. When an inorganic material is used, the accuracyof the area of the opening 33 b is relatively highly accurate ascompared with the case in which a photosensitive resin is used. However,a quite long deposition time is required for forming an inorganicinsulating film having a thickness of a few μm using a vapor phaseprocess such as sputtering, and etching for forming the opening 33 btakes a long time as well. Therefore, using an inorganic material forthe material of forming the insulating film 33 arises another problemthat the electronic component having the capacitor element 611 needsmore costs than the case of using an organic material.

There is also a method of forming the column shaped conductor part ofthe upper conductor 623 by etching (subtractive process). However,generally, the accuracy of the shape of the conductor is more dropped asthe conductor is formed thicker. Since it is necessary to thicken theinsulating film 33 to a few μm, it is also necessary to thicken thecolumn shaped conductor part of the upper conductor 623. Therefore, eventhough the column shaped conductor part of the upper conductor 623 isformed by etching, the capacitor element 611 has problems that theelectrode area cannot be formed highly precisely and the capacitancevalue cannot be obtained highly accurately.

In addition, as shown in FIG. 37, the insulating film 33 around theopening 33 b has a tapered shape. The insulating film 33 at the tip endpart in a tapered shape indicated by circle A in FIG. 37 is thin, andfunctions as the dielectric film of the capacitor element 611 along withthe dielectric film 31 directly formed thereunder. However, since thearea of the opening 33 b as well as the tapered shape of the insulatingfilm 33 have variations, the film thickness of the tip end part in atapered shape and the area of the opening 33 b are varied. Therefore, aproblem arises that the variations in tapered shape also affects thecapacitance value of the capacitor element 611.

In addition, the insulating film 33 at the tip end part in a taperedshape is thin, and hardly has the insulating properties. Moreover, thedielectric film 31 on the end part of the lower conductor 21 indicatedby B in FIG. 37 might be partially broken. This might cause leakagecurrent to be carried through the insulating film 33 at the tip end partin a tapered shape and the broken portion of the dielectric film 31.When leakage current is carried, the insulating film 33 is damaged tocause a problem that the capacitor element 611 does not function as acapacitor.

FIG. 38 shows a thin film capacitor 811 disclosed in Patent Reference 2.As shown in FIG. 38, the thin film capacitor 811 is configured to inturn form a lower electrode layer 821, a dielectric layer 831, a firstupper electrode layer 823, and a second upper electrode layer 825 on aninsulating substrate 851, having a thickness of 0.005 (μm)≦t1′≦1 (μm),2×t1′≦t2≦10 (μm) where the thickness of the first upper electrode layer823 is t1′, and the thickness of the second upper electrode layer 825 ist2′.

The first upper electrode layer 823 serves as a contact layer to obtainsufficient adhesion properties with the dielectric layer 831 working asthe upper electrode layer as well as serves as a role to decide the thinfilm capacitance value of the capacitor by the dimensions (area) of thislayer. The second upper electrode layer 825 reduces the conductionresistance of the upper electrode as the main conductor of the upperelectrode of the thin film capacitor 811, which has excellent bondingproperties for wire bonding and ribbon bonding and soldering propertiesfor a solder.

The thin film capacitor 811 has the upper electrode layer in the layeredstructure of the first upper electrode layer 823 on the dielectric layer831 side and the second upper electrode layer 825 formed thereon, inwhich the thickness t1′ of the first upper electrode layer 823 isreduced to 0.005 to 1 (μm) and the thickness t2′ of the second upperelectrode layer 825 is thickened to 2×t1′ to 10 (μm). Thus, since sideetching does not occur in the first upper electrode layer 823 as before,the variations in the dimensions can be eliminated, and the counterelectrode area can be controlled accurately, whereby the occurrence ofvariations in the capacitance value can be removed. In addition, sincethe second upper electrode layer 825 has sufficient thickness, it can beprovided with excellent wire bonding properties and low conductionresistance which are considered to be necessary for the upper electrodelayer. Consequently, a small sized, highly accurate thin film capacitor811 can be provided which has very small variations in the capacitancevalue.

For methods of forming the second upper electrode layer 825, forexample, such a method that a metal film such as titanium, tantalum, ornickel-chrome to be the first upper electrode layer 823 and a metal filmsuch as copper, gold, or aluminum to be the second upper electrode layer825 are deposited on the substrate having layers up to the dielectriclayer 831 formed in a predetermined thickness by vapor deposition andsputtering.

Subsequently, a photoresist is formed in a desired pattern shapecorresponding to the second upper metal film 825 on the surface of themetal film to be the second upper metal film 825 by photolithographictechnique, the photoresist is used as a mask for pattern etching usingan etching solution matched with the second upper metal film 825 (forexample, ammonium persulfate aqueous solution for copper), and thesecond upper electrode layer 825 in a predetermined shape and dimensionsis formed.

However, the thin film capacitor 811 disclosed in Patent Reference 2 hasa problem that it cannot be formed in one piece with the other circuitdevices such as an inductor element and a resistance element and itcannot be adapted to a composite component. In addition, the thin filmcapacitor 811 has a problem that it is difficult to form the thin filmcapacitor 811 to have a super multilayer form by laminating thedielectric layer 831, the first upper electrode layer 823 and the secondupper electrode layer 825 on the second upper electrode layer 825.

In addition, in the thin film capacitor 811, it is likely to etch thefirst upper electrode layer 823 as well in pattern etching the secondupper metal film 825. Therefore, the thin film capacitor 811 hasproblems that the first upper electrode layer 823 cannot be formed in adesired shape and dimensions and that the accuracy of the counter areais not highly accurate.

-   Patent Reference 1: JP-A-2002-25854-   Patent Reference 2: JP-A-10-135077-   Patent Reference 3: JP-A-2002-33559-   Patent Reference 4: JP-A-2003-17366-   Patent Reference 5: Japanese Patent No. 3193973

SUMMARY OF THE INVENTION

An object of the invention is to provide an electronic component whichcan obtain the capacitance value of a capacitor element highlyaccurately.

The object is achieved by an electronic component including: a firstconductor which is formed on a substrate; a dielectric film which isformed on the first conductor; and a second conductor which is formed onthe dielectric film and thinner than the first conductor, wherein acapacitative element is configured of the first conductor, the secondconductor and the dielectric film.

In the electronic component according to the invention, an electrodearea of the capacitative element is defined by an area of the secondconductor.

In the electronic component according to the invention, t1>t2 and x≦t2,where a thickness of the first conductor is t1, a thickness of thesecond conductor is t2, and a particle diameter of the second conductoris x.

In the electronic component according to the invention, an entiresurface of the second conductor is flat.

In the electronic component according to the invention, it furtherincludes an insulating film which is formed on the second conductor.

In the electronic component according to the invention, an opening isformed in a part of the insulating film on the second conductor in whicha surface of the second conductor is exposed.

In the electronic component according to the invention, it furtherincludes a third conductor which is formed in the opening and is thickerthan the second conductor.

In the electronic component according to the invention, the thirdconductor is extended over the insulating film.

In the electronic component according to the invention, the firstconductor and the third conductor are formed in different layers.

In the electronic component according to the invention, a surface of theinsulating film is flat.

In the electronic component according to the invention, the insulatingfilm is formed on almost throughout a surface of the substrate.

In the electronic component according to the invention, it furtherincludes: a fourth conductor which is formed in a same layer as thefirst conductor; and a fifth conductor which is faced to the fourthconductor through the insulating film.

In the electronic component according to the invention, a film thicknessof the dielectric film is thinner than a film thickness of theinsulating film.

In the electronic component according to the invention, a dielectricconstant of the dielectric film is higher or equal to a dielectricconstant of the insulating film.

In the electronic component according to the invention, the dielectricfilm is formed only on the first conductor.

In addition, the object is achieved by a method of fabricating anelectronic component including the steps of: forming a first conductoron a substrate; forming a dielectric film on the first conductor;forming a second conductor which is thinner than the first conductor onthe dielectric film, wherein a capacitative element is configured of thefirst conductor, the second conductor and the dielectric film; formingan insulating film on the second conductor; forming an opening in theinsulating film in which a surface of the second conductor is exposed;and forming a third conductor which is thicker than the second conductorin the opening.

According to the invention, the electronic component which can obtainthe capacitance value of the capacitor element highly accurately can berealized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1C show diagrams depicting an electronic component 1according to a first embodiment of the invention;

FIGS. 2A to 2C show cross sections depicting a method of fabricating theelectronic component 1 according to the first embodiment of theinvention (first one);

FIGS. 3A to 3C show cross sections depicting a method of fabricating theelectronic component 1 according to the first embodiment of theinvention (second one);

FIGS. 4A to 4C show cross sections depicting a method of fabricating theelectronic component 1 according to the first embodiment of theinvention (third one);

FIGS. 5A to 5C show cross sections depicting a method of fabricating theelectronic component 1 according to the first embodiment of theinvention (fourth one);

FIGS. 6A to 6C show cross sections depicting a method of fabricating theelectronic component 1 according to the first embodiment of theinvention (fifth one);

FIG. 7 shows a cross section depicting a method of fabricating theelectronic component 1 according to the first embodiment of theinvention (sixth one);

FIGS. 8A and 8B show diagrams depicting an exemplary modification of theelectronic component 1 according to the first embodiment of theinvention;

FIGS. 9A and 9B show diagrams depicting an exemplary modification of theelectronic component 1 according to the first embodiment of theinvention;

FIGS. 10A and 10B show diagrams depicting an exemplary modification ofthe electronic component 1 according to the first embodiment of theinvention;

FIGS. 11A and 11B show diagrams depicting an exemplary modification ofthe electronic component 1 according to the first embodiment of theinvention;

FIG. 12 shows a cross section depicting an electronic component 101according to a second embodiment of the invention;

FIGS. 13A to 13C show cross section depicting a method of fabricatingthe electronic component 101 according to the second embodiment of theinvention (first one);

FIG. 14 shows a cross section depicting a method of fabricating theelectronic component 101 according to the second embodiment of theinvention (second one);

FIG. 15 shows a cross section depicting the electronic component 201according to a third embodiment of the invention;

FIG. 16 shows a cross section depicting an electronic component 301according to a fourth embodiment of the invention;

FIG. 17 shows a cross section depicting the electronic component 401according to a fifth the embodiment of the invention;

FIGS. 18A and 18B show cross sections depicting a method of fabricatingthe electronic component 401 according to the fifth embodiment of theinvention (first one);

FIGS. 19A to 19C show cross sections depicting a method of fabricatingthe electronic component 401 according to the fifth embodiment of theinvention (second one);

FIGS. 20A to 20C show cross sections depicting a method of fabricatingthe electronic component 401 according to the fifth embodiment of theinvention (third one);

FIGS. 21A to 21C show cross sections depicting a method of fabricatingthe electronic component 401 according to the fifth embodiment of theinvention (fourth one);

FIGS. 22A to 22C show cross sections depicting a method of fabricatingthe electronic component 401 according to the fifth embodiment of theinvention (fifth one);

FIG. 23 shows a cross section depicting an electronic component 501according to a sixth embodiment of the invention;

FIGS. 24A to 24C show cross sections depicting a method of fabricatingthe electronic component 501 according to the sixth embodiment of theinvention (first one);

FIGS. 25A to 25C show cross sections depicting a method of fabricatingthe electronic component 501 according to the sixth embodiment of theinvention (second one);

FIGS. 26A to 26C show cross sections depicting a method of fabricatingthe electronic component 501 according to the sixth embodiment of theinvention (third one);

FIGS. 27A to 27C show cross sections depicting a method of fabricatingthe electronic component 501 according to the sixth embodiment of theinvention (fourth one);

FIGS. 28A to 28C show cross sections depicting a method of fabricatingthe electronic component 501 according to the sixth embodiment of theinvention (fifth one);

FIG. 29 shows a cross section depicting an electronic component 601according to a seventh embodiment of the invention;

FIG. 30 shows a cross section depicting an electronic component 701according to an eighth embodiment of the invention;

FIGS. 31A to 31C show cross sections depicting a method of fabricatingthe electronic component 701 according to the eighth embodiment of theinvention (first one);

FIGS. 32A to 32C show cross sections depicting a method of fabricatingthe electronic component 701 according to the eighth embodiment of theinvention (second one);

FIGS. 33A to 33C show cross sections depicting a method of fabricatingthe electronic component 701 according to the eighth embodiment of theinvention (third one);

FIGS. 34A and 34B show cross sections depicting a method of fabricatingthe electronic component 701 according to the eighth embodiment of theinvention (fourth one);

FIGS. 35A and 35B show diagrams depicting the capacitor element 411before;

FIG. 36 shows a cross section depicting the thin film capacitor element1011 disclosed in Patent Reference 1;

FIG. 37 shows a cross section depicting the capacitor element 611proposed by the inventors; and

FIG. 38 shows a cross section depicting the thin film capacitor 811disclosed in Patent Reference 2;

DETAILED DESCRIPTION OF THE INVENTION First Embodiment

An electronic component according to a first embodiment of the inventionwill be described with reference to FIGS. 1A to 11B. First, anelectronic component 1 according to the embodiment will be describedwith reference to FIGS. 1A to 1C. FIG. 1A shows a plan view depictingthe electronic component 1, and FIG. 1B shows a cross section cut atline A-A shown in FIG. 1A. In addition, FIG. 1C shows an equivalentcircuit diagram depicting the electronic component 1. In FIG. 1A, ahidden line is depicted by a dotted line.

As shown in FIGS. 1A and 1B, the electronic component 1 has a capacitorelement (capacitative element) 11 formed by thin film formationtechnique and an inductor element 13 which is electrically connected tothe capacitor element 11, having an overall outer appearance of arectangular parallelepiped shape. In FIG. 1A, the ratio between thelength of the long side of the electronic component 1 laterally extendedand the length of the short side vertically extended is about 2:1. Asshown in FIG. 1C, the capacitor element 11 is serially connected to theinductor element 13 to configure a series resonant circuit.

As shown in FIG. 1B, in the electronic component 1 according to theembodiment, for a substrate, a smooth substrate 51 is used on thesurface of which a planarized layer 52 is formed. For example, thesubstrate 51 is formed of alumina (Al₂O₃). The planarized layer 52 isformed of alumina, and the surface of the planarized layer 52 ispolished and made flat by CMP (chemical-mechanical polishing).

The electronic component 1 has a coil conductor 12 which is formed onthe planarized layer 52 of the substrate 51 in a spiral shape when thesubstrate 51 is seen in the normal direction of the substrate surface,and via openings 31 a and 33 a which are formed in a dielectric film 31and an insulating film 33 on the end part on the inner radius side ofthe coil conductor 12.

In the via openings 31 a and 33 a and on the insulating film 33, aconductor 61 is formed which contacts with the end part on the innerradius side of the coil conductor 12 at the via opening 31 a. Theinductor element 13 is formed of the coil conductor 12 and the conductor61. The end part on the outer radius side of the coil conductor 12 iselectrically connected to a lower conductor 21. The coil conductor 12and the lower conductor 21 are formed in one piece in the same layer.The conductor 61 and the conductor 25 are current carrying terminals forthe electronic component 1.

The coil conductor 12 is configured of an underlying conductor 12 a oftitanium (Ti)/copper (Cu) or chromium (Cr)/Cu which is formed on theplanarized layer 52 of the substrate 51, and a conductor 12 b of Cuwhich is formed on the underlying conductor 12 a. As shown in FIG. 1A,the coil conductor 12 is formed of a single wound coil.

To the coil conductor 12, the conductor 61 is electrically connected.The conductor 61 is extended over from the via opening 33 a to theinsulating film 33, and is formed in a slim rectangular shape from thevia opening 33 a to the rim part on the short side of the electroniccomponent 1. The conductor 61 is configured of an underlying conductor61 a of Ti/Cu which is formed on the coil conductor 12, the dielectricfilm 31 and the insulating film 33, and a conductor 61 b of Cu which isformed on the underlying conductor 61 a. The coil conductor 12 is facedto the conductor 61 formed on the insulating film 33 through theinsulating film 33.

The via part of the conductor 61 is formed in the via openings 31 a and33 a formed in the dielectric film 31 and the insulating film 33, andthe side part of which is covered with the dielectric film 31 and theinsulating film 33. Therefore, the via part can secure reliableconnection and insulating properties, and can improve the reliability ofconnection of the via part. Accordingly, the reliability of theelectronic component 1 is enhanced.

In addition, as shown in FIG. 1B, the electronic component 1 has a lowerconductor (first conductor) 21 which is formed on the planarized layer52 of the substrate 51, a dielectric film 31 which is formed on thelower conductor 21, and an upper conductor (second conductor) 23 whichis formed on the dielectric film 31 and is thinner than the lowerconductor 21. The capacitor element (capacitative element) 11 isconfigured of the lower conductor 21, the dielectric film 31 and theupper conductor 23.

The capacitor element 11 is configured of the lower conductor 21, thedielectric film 31 and the upper conductor 23 which are in turnlaminated and formed on the planarized layer 52 of the substrate 51. Asshown in FIG. 1A, the lower conductor 21 has a rectangular shape whenthe substrate 51 is seen in the normal direction of the substratesurface. The lower conductor 21 is formed of the same material as thecoil conductor 12 at the same time in the same layer.

The coil conductor 12 and the lower conductor 21 are relatively thickerwith respect to the upper conductor 23. Therefore, the equivalent seriesresistance (ESR) of the capacitor element 11 is reduced to decrease thetransmission loss. The desired thickness of the coil conductor 12 andthe lower conductor 21 is varied depending on the frequencycharacteristics that are desired by the electronic component 1. Forexample, when the electronic component 1 is used for a bandpass filterin a 2.4 GHz band, preferably, the thickness t1 of the coil conductor 12and the lower conductor 21 is t1≧5 (μm). In the embodiment, since theelectronic component 1 is a bandpass filter in a 2.4 GHz band, it isrequired for high attenuation characteristics in order to remove noisein frequency bands other than this frequency band. Depending on thefrequency bands to process, considerations are required for setting thethickness of the conductor. In the tendency, when the frequency band toprocess is high, the thickness of setting the conductor can be madethin, and the attenuation characteristics necessary as the bandpassfilter can be obtained. Thus, in order to take account of theattenuation characteristics in low frequency domain, it is necessary tothicken the thickness of setting the conductor. Particularly, frequencybands for systems such as cellular telephones are set in the frequencydomain lower than 2.4 GHz, and it is important to take account ofsetting the thickness of the conductor for these frequency bands of 800MHz, 900 MHz, 1500 MHz, 1700 MHz, 1900 MHz, and 2100 MHz. In addition,in consideration of the variations in the thickness in fabrication, forexample, the thickness t1 of the coil conductor 12 and the lowerconductor 21 is t1=8 (μm).

The lower conductor 21 is configured of an underlying conductor 21 a oftitanium (Ti)/copper (Cu) which is formed on the planarized layer 52 ofthe substrate 51, and a conductor 21 b of Cu which is formed on theunderlying conductor 21 a. Since the lower conductor 21 is formed of aconductor material of low resistance such as Cu, the ESR of thecapacitor element 11 can be decreased. The lower conductor 21 has anelectrode part which is faced to the upper conductor 23 as it sandwichesthe dielectric film 31 therewith and functions as the electrode of thecapacitor element 11, and a lead conductor part which is lead to connectthe electrode part to the coil conductor 12. The electrode part is asquare area which occupies almost the center part of the lower conductor21 and the length of one side is l indicated by a broken line in FIG.1A. The lead conductor part is a rectangular area sandwiched by theelectrode part and the coil conductor 12. The lead conductor part has awire shape of wide width, and it is relatively short. Thus, the ESR andequivalent series inductance (ESL) of the capacitor element 11 can bedecreased.

As shown in FIG. 1B, the dielectric film 31 is formed on the coilconductor 12, the lower conductor 21 and the planarized layer 52 of thesubstrate 51. The dielectric film 31 is formed over almost throughoutthe surface of the substrate 51 except the via opening 31 a, and coversalmost throughout the top and the side surface of the coil conductor 12and the lower conductor 21. For example, the film thickness d of thedielectric film 31 is 0.1 (μm), which is formed thinner than that of thelower conductor 21. For the material of the dielectric film 31, forexample, alumina, silicon nitride (Si₄N₃), silicon dioxide (SiO₂),tantalum oxide (Ta₂O₅), or aluminium nitride (AlN) is used. The filmthickness d of the dielectric film 31 is made uniform.

As shown in FIG. 1B, the upper conductor 23 is formed on the dielectricfilm 31 on the electrode part of the lower conductor 21. The upperconductor 23 is a square area which the length of one side is lindicated by a broken line in FIG. 1A. For example, the length l is 100(μm). The accuracy of the position of forming the upper conductor 23depends on the positioning accuracy of the substrate inphotolithographic process steps. As shown in FIG. 1A, the upperconductor 23 is formed more inside by the amount of the accuracy of theformed position than the lower conductor 21 when the substrate surfaceof the substrate 51 is seen in the normal direction. Thus, the influenceof the variations in the position of forming the upper conductor 23 uponthe capacitance value of the capacitor element 11 can be eliminated. Theelectrode area of the capacitor element 11 is defined by the area l² ofthe upper conductor 23. The capacitance value of the capacitor element11 is defined by the area l² of the upper conductor 23, and the filmthickness d and the dielectric constant of the dielectric film 31sandwiched between the upper conductor 23 and the lower conductor 21.The surface of the upper conductor 23 is flat throughout the surface.

The upper conductor 23 is formed thinner than the lower conductor 21.Generally, the accuracy of the shape of the conductor is more dropped asthe conductor is formed thicker. Since the upper conductor 23 is formedthinner, the upper conductor 23 in a highly accurate shape can beobtained. Therefore, the area accuracy of the upper conductor 23 facedto the lower conductor 21 is highly accurate, and the electrode area ofthe capacitor element 11 can be formed highly precisely.

In addition, the upper conductor 23 is formed by a film depositionprocess such as sputtering and vapor deposition with a vacuum depositionapparatus. Therefore, since the upper conductor 23 with uniformthickness distribution and small particle diameter can be formed, theetched amount of side etching can de decreased even though side etchingoccurs in patterning the upper conductor 23 into a desired shape.Accordingly, the influence of side etching upon the accuracy of theshape of the upper conductor 23 can be made small, and the accuracy ofthe shape of the upper conductor 23 can be made more highly accurately.Therefore, the area accuracy of the upper conductor 23 is made morehighly accurately, and the electrode area of the capacitor element 11can be formed more highly precisely.

Preferably, the thickness t2 of the upper conductor 23 is x≦t2, wherethe particle diameter of the upper conductor 23 is x (x<1 (μm)). Thethickness t2 of the upper conductor 23 is set within that range, wherebythe upper conductor 23 in a highly accurate shape can be obtained. Theparticle diameter x of the upper conductor 23 is varied depending onfilm deposition processes. For example, when the upper conductor 23 isdeposited by sputtering, the particle diameter x of the upper conductor23 is about 3 to 5 (nm). When the thickness t2 is thicker than 1 (μm),the surface shape of the upper conductor 23 is roughened, the accuracyof the shape of the upper conductor 23 cannot be highly accurate, andthe electrode area of the capacitor element 11 cannot be formed highlyprecisely. In the embodiment, the thickness t2 of the upper conductor 23is 130 (nm). The upper conductor 23 is configured of the conductor of Tihaving a thickness of 30 (nm) which is formed on the dielectric film 31and the conductor of Cu having a thickness of 100 (nm) which is formedon the conductor of Ti.

The method of forming the upper conductor 23 may be any one of etching(subtractive process) and deposition (additive process). In addition,the method may be ink jet printing or screen printing using conductivematerials.

The upper conductor 23 is formed on the flat part other than the endpart of the lower conductor 21 as it avoids the end part. Thus, eventhough the film thickness of the dielectric film 31 is made thin or notformed at the end part of the lower conductor 21, the lower conductor 21is not short circuited with the upper conductor 23. Therefore, thebreakdown limit of the withstand voltage value and the insulatingproperties of the electronic component 1 are improved, and the qualityvariations in the fabricated electronic component 1 are suppressed.

In addition, since it is unnecessary to thicken the film thickness ofthe dielectric film 31 in order to prevent a short circuit between thelower conductor 21 and the upper conductor 23, the film thickness d ofthe dielectric film 31 can be formed one tenth of the film thicknessbefore (2 to 3 (μm)), and the capacitor element 11 of high capacitancecan be obtained. In addition, even though the electrode area 12 of thecapacitor element 11 is made small, the sufficient capacitance can beobtained, and thus a reduction in size of the electronic component 1 canbe realized. For example, it is possible to intend a reduction in sizeof the electronic component 1 where the length l of one side of theupper conductor 23 is set to the length shorter than 100 (μm) such as 50(μm) or 30 (μm) or 5 (μm). Therefore, the electronic component 1 can beadapted to a 1608 type component (the length of the long side is 1.6 mmand the length of the short side is 0.8 mm), a 1005 type component (thelength of the long side is 1.0 mm and the length of the short side is0.5 mm) or smaller chip components. In addition, since the sufficientcapacitance can be obtained without forming the capacitor element 11 inmultilayer, the electronic component 1 can be reduced in thickness.

As shown in FIG. 1B, the insulating film 33 is formed on the end part ofthe upper conductor 23 and the dielectric film 31. For example, the filmthickness i of the insulating film 33 is 5 (μm). For example, theinsulating film 33 is formed of a photosensitive resin forsemiconductors (photoresist for semiconductors). A photosensitive resinfor semiconductors is used for the material of forming the insulatingfilm 33, whereby the insulating film 33 can be obtained which isexcellent in the insulating properties, environmental resistance, costs,and the accuracy of the thickness and flatness. For the material offorming the insulating film 33, photosensitive polyimides orphotosensitive epoxy materials may be used. In addition, inorganicmaterials such as alumina may be used. The material for the insulatingfilm 33 is demanded for heat resistance properties. The insulating film33 is formed as isolated from the lower conductor 21 and the coilconductor 12 by the dielectric film 31, and does not directly contactwith the lower conductor 21 and the coil conductor 12. For thedielectric film 31, a material having a higher dielectric constant thanthat of the insulating film 33. The film thickness d of the dielectricfilm 31 is thinner than the film thickness i of the insulating film 33.

In the insulating film 33, an opening 33 b is formed which is formed onthe upper conductor 23 through which the surface of the upper conductor23 is exposed. The opening 33 b has a square shape, for example, whenthe substrate 51 is seen in the normal direction of the substratesurface. In addition, as shown in FIG. 1B, the insulating film 33 aroundthe opening 33 b has a tapered shape. The insulating film 33 is formedalmost throughout the surface of the substrate 51 except the via opening33 a and the opening 33 b. The insulating film 33 near the outer rim ofthe electronic component 1 (near a cutting line of a product) may beremoved.

Different from the thin film capacitor element 1011 disclosed in PatentReference 1, the electronic component 1 does not have the insulatinglayer 1033 in a shape protruded toward the substrate surface, and theinsulating film 33 is formed almost throughout the surface of thesubstrate 51. Therefore, the electronic component 1 can be easily formedin a super multilayer form. For example, the dielectric film 31, theupper conductor 23 and the conductor 25 are alternately laminated on theconductor 25, whereby the capacitor element 11 of high capacitance canbe obtained. Moreover, since the protruded insulating layer 1033 is notformed in the rim part of the capacitor element 11, the inductor element13 can be formed near the capacitor element 11. Accordingly, a reductionin size of the electronic component 1 can be realized.

In addition, different from the thin film capacitor 811 disclosed inPatent Reference 2, since the electronic component 1 has the insulatingfilm 33 almost throughout the surface of the substrate 51, the othercircuit devices such as the inductor element 13 can be formed in onepiece with the capacitor element 11, and the electronic component 1 canbe adapted to a composite component. In addition, different from thethin film capacitor 811 disclosed in Patent Reference 2, since theinsulating film 33 is formed, the electronic component 1 can be easilyformed in a super multilayer form.

As shown in FIG. 1B, the conductor (third conductor) 25 is formed on theupper conductor 23 in the opening 33 b. In addition, the conductor 25 isextended over the insulating film 33 from the opening 33 b to the rimpart on the short side of the electronic component 1. The conductor 25is not formed in the same layer as the lower conductor 21. As shown inFIG. 1A, the conductor 25 has a rectangular shape when the substratesurface of the substrate 51 is seen in the normal direction.

As shown in FIG. 1B, for example, a protective film 54 having a filmthickness of 30 (μm) is formed throughout the surface of the conductor25, the insulating film 33 and the conductor 61. For example, theprotective film 54 is formed of alumina.

The thickness t3 of the conductor 25 is formed thicker than the upperconductor 23. Thus, even though the upper conductor 23 is formed thin,the ESR and ESL of the capacitor element 11 can be decreased. Therefore,the high frequency characteristics such as the Q characteristics and theself resonant frequency (SRF) of the capacitor element 11 are improvedto decrease the transmission loss. Accordingly, the capacitor element 11with small transmission loss can be realized which can be used for highfrequencies as well. For example, the thickness t3 of the conductor 25is 8 (μm) that is equal to the thickness t1 of the coil conductor 12 andthe lower conductor 21.

The conductor 25 is formed of the same material as that of the conductor61 at the same time in the same layer. The conductor 25 is configured ofan underlying conductor 25 a of Ti/Cu which is formed on the upperconductor 23 and the insulating film 33, and a conductor 25 b of Cuwhich is formed on the underlying conductor 25 a. The conductor 25 has acolumn shaped conductor part which is formed in the opening 33 b, and alead conductor part which is formed over the insulating film 33 from theupper part of the opening 33 b to the rim part on the short side of theelectronic component 1 in order to connect the upper conductor 23 to anexternal electrode (not shown) formed on the side surface of theelectronic component 1. The lead conductor part has a wire shape of widewidth, and it is relatively short. Therefore, the ESR and equivalentseries inductance (ESL) of the capacitor element 11 can be decreased.

It is necessary to form the conductor 25 which contacts with the upperconductor 23 so as not to extend off the upper conductor 23 when thesubstrate surface of the substrate 51 is seen in the normal direction.When the conductor 25 which contacts with the upper conductor 23 isformed to extend off the upper conductor 23, parasitic capacitance isformed between the lower conductor 21 and the extended portion, and thecapacitance value of the capacitor element 11 cannot be obtained highlyaccurately. In consideration of the accuracy of the formed position andshape of the opening 33 b, the conductor 25 which contacts with theupper conductor 23 is formed inside the upper conductor 23 when thesubstrate 51 is seen in the normal direction of the substrate surface.Thus, the influence of the variations in the position and shape of theopening 33 b upon the accuracy of the capacitance value of the capacitorelement 11 can be eliminated. In addition, preferably, the area (thearea of the opening 33 b) of the conductor 25 which contacts with theupper conductor 23 is almost equal to the area of the upper conductor23. Therefore, the contact area of the upper conductor 23 to theconductor 25 is increased to decrease the ESR of the capacitor element11, and the reliability of connection can be obtained.

In addition, the conductor 25 is extended over from the opening 33 b tothe insulating film 33, and is not formed in the same layer as the lowerconductor 21. Thus, even though the film thickness of the dielectricfilm 31 is thin or not formed at the end part of the lower conductor 21,the lower conductor 21 is not short circuited with the conductor 25.Therefore, the breakdown limit of the withstand voltage value and theinsulating properties of the electronic component 1 are improved, andthe quality variations in the fabricated electronic component 1 aresuppressed.

In addition, different from the capacitor element 611 shown in FIG. 37,the upper conductor 23 is formed between the insulating film 33 at thetip end part in a tapered shape and the dielectric film 31 on the endpart of the lower conductor 21. Thus, even though the dielectric film 31on the end part of the lower conductor 21 is not partially formed, theleakage current carried between the insulating film 33 at the tip endpart in a tapered shape and the dielectric film 31 on the end part ofthe lower conductor 21 can be prevented. Therefore, the breakdown limitof the withstand voltage value and the insulating properties of theelectronic component 1 are improved, and the quality variations in thefabricated electronic component 1 are suppressed.

The thin film capacitor element 1011 disclosed in Patent Reference 1 hasthe structure in which the side surface of the lower electrode 1021 isfaced to the upper electrode 1023 through the insulating layer 1033.Since the insulating layer 1033 becomes thinner as the thin filmcapacitor element 1011 is reduced in size, the ratio of parasiticcapacitance to the capacitance value of the thin film capacitor element1011 becomes large.

On the other hand, the electronic component 1 according to theembodiment has the structure in which the conductor 25 is not faced tothe side surface of the lower conductor 21. Thus, regardless of the sizeof the electronic component 1, the parasitic capacitance that occursbetween the side surface of the lower conductor 21 and the conductor 25is hardly changed. Therefore, even though the electronic component 1 isreduced in size, the ratio of the parasitic capacitance to thecapacitance value of the capacitor element 11 is not increased.Therefore, the electronic component 1 in small size can be realizedwhich can obtain the capacitance value of the capacitor element 11highly accurately.

Generally, since the capacitance value of the capacitor is inverselyproportional to the distance between electrodes, the parasiticcapacitance that occurs between the lower conductor 21 and the leadconductor part of the conductor 25 becomes small when the film thicknessi of the insulating film 33 is thickened. On this account, the parasiticcapacitance (the amount of deviation in the capacitance value) of thecapacitor element 11 is almost inversely proportional to the filmthickness i of the insulating film 33.

Therefore, when the insulating film 33 is thickened, the parasiticinductance and the parasitic capacitance that occur between the lowerconductor 21 and the conductor 25 are decreased. Accordingly, theaccuracy of the capacitance value of the capacitor element 11 can beenhanced. In addition, the degradation of the transmissioncharacteristics in the high frequency domain can be suppressed.Moreover, a desired circuit constant can be obtained, and the highfrequency circuit design is facilitated.

In the thin film capacitor element, in the case in which highercapacitance is obtained in a smaller counter area, capacitive couplingto surrounding wirings affects more greatly on the capacitance value.Thickening the film thickness i of the insulating film 33 is effectivewhen a desired capacitance value of the capacitor element 11 is obtainedin order to intend a reduction in the size of the capacitor element 11.In addition, the unevenness of the film thickness i of the insulatingfilm 33 is decreased to suppress the fluctuations in the capacitancevalue for every product.

In addition, when the insulating film 33 is thickened, the straycapacitance between the coil conductor 12 and the conductor 61 aredecreased. Thus, it is intended that the self resonant frequency and theantiresonance frequency of the inductor element 13 are adapted to highfrequencies and the Q characteristics are improved. For example, whenthe electronic component is used for a filter circuit in accordance withan LC resonant circuit having the same structure as that of thecapacitor element 11 and the inductor element 13, insertion loss isreduced, the suppression of the amount of attenuation of the out-of-bandcharacteristics is improved, or the steepness of cut off domains isimproved. In the case in which the insulating film 33 is formed thinnerto intend a thin capacitor element 11, the distance between the lowerconductor 21 and the conductor 25 is actively changed to reduce the filmthickness of the insulating film 33 and the height of the opening 33 b,whereby capacitive coupling that occurs between the lower conductor 21and the lead conductor part of the conductor 25 can be actively used asthe capacitance of the capacitor element 11 and the parasiticcapacitance of the inductor element 13.

In addition, the film thickness i of the insulating film 33 is thickenedto decrease magnetic coupling and capacitive coupling to the wiringsfaced to the wirings of the coil conductor 12 and the coil conductor 12can be decreased (for example, the conductor 61, and wirings for ground,power supply, shield, the inductor element and the capacitor element 11and so on).

In addition, the film thickness i or the dielectric constant of theinsulating film 33 is adjusted to intentionally generate electromagneticcoupling and capacitive coupling, and the performance of thetransmission characteristics is exploited in a desired frequency band,whereby the characteristics of the electronic component 1 can beimproved. The film thickness i or the dielectric constant of theinsulating film 33 is adjusted to actively utilize parasitic components,whereby magnetic coupling is performed efficiently, alternate currentcomponents are effectively exploited, and direct current components aredecreased, for example, to reduce the transmission loss of theelectronic component 1.

As described above, in the electronic component 1 according to theembodiment, the electrode area of the capacitor element 11 is defined bythe area 12 of the upper conductor 23, not by the area of the opening 33b. The accuracy of the electrode area is not affected by variations inthe area of the opening 33 b caused by the cure and shrinkage of theinsulating film 33, the variations in the tapered shape of theinsulating film 33, and the methods of forming the opening 33 b. Inaddition, since the upper conductor 23 is formed thinner than the lowerconductor 21, the upper conductor 23 in a highly accurate shape can beobtained. Therefore, the area accuracy of the upper conductor 23 ishighly accurate, and the capacitor element 11 can be obtained which canobtain the capacitance value highly accurately.

A method of fabricating the electronic component 1 according to theembodiment will be described with reference to FIGS. 2A to 7. Although alarge number of the electronic components 1 are formed on a wafer at thesame time, FIGS. 2A to 7 show a device forming area for a singleelectronic component 1. FIGS. 2A to 7 show cross sections depicting thefabrication process steps of the electronic component 1 according to theembodiment.

In the embodiment, for a substrate, the substrate 51 with a planarizedsurface is used. First, the surface of alumina formed on throughout thesurface of the substrate 51 formed of alumina (Al₂O₃) is polished by CMP(chemical-mechanical polishing) to form the planarized layer 52.

Subsequently, as shown in FIG. 2A, for example, titanium (Ti) having afilm thickness of about 30 (nm) and copper (Cu) having a film thicknessof about 100 (nm) are in turn laminated on the planarized layer 52 ofthe substrate 51 by sputtering to form an underlying conductor 71. Then,for example, a photosensitive resin having a thickness of about 8 (μm)is applied to throughout the surface of the underlying conductor 71 byspin coating to form a photosensitive resin layer 81. Subsequently, asshown in FIG. 2B, the photosensitive resin layer 81 is exposed anddeveloped, and an opening 81 a in a rectangular shape and an opening 81b in a spiral shape are formed in the photosensitive resin layer 81 whenthe substrate 51 is seen in the normal direction of the substratesurface. The end part on the outer radius side of the opening 81 b isconnected to the opening 81 a.

Then, as shown in FIG. 2C, a conductor of Cu having a thickness of 9 to10 (μm) is formed on the underlying conductor 71 in the openings 81 aand 81 b by electrolytic plating, and the surface of the conductor ispolished by CMP to form the conductors 12 b and 21 b having a thicknessof about 8 (μm). Subsequently, as shown in FIG. 3A, the photosensitiveresin layer 81 is removed.

Then, as shown in FIG. 3B, the underlying conductor 71 exposed betweenthe conductors 12 b and 21 b is removed by dry etching or wet etching toform the underlying conductor 21 a configured of the underlyingconductor 71 under the conductor 21 b and the underlying conductor 12 aconfigured of the underlying conductor 71 under the conductor 12 b. Bythe process steps described above, the lower conductor (first conductor)21 is formed in the layered structure in which the underlying conductor21 a and the conductor 21 b are laminated with each other, and the coilconductor 12 is formed in the layered structure in which the underlyingconductor 12 a and the conductor 12 b are laminated with each other.

In the embodiment, although semi-additive process (deposition) is usedfor the method of forming the lower conductor 21 and the coil conductor12, subtractive process (etching), damascene, paste, or lift-off may beused for methods of forming the conductor. The conductor 25 and theconductor 61 described later are formed by the same method as that ofthe lower conductor 21 and the coil conductor 12. In addition, thewiring layers for the coil conductor 12 and the conductor 61 describedlater may be any one of the wiring layer of the lower conductor 21 andthe wiring layer of the conductor 25, which can be freely arranged inconsideration of the ease of the wiring design and the electriccharacteristics and shape of the inductor element 13.

In the process steps forming the coil conductor 12 and the lowerconductor 21, the material for forming the photosensitive resin layer 83and the photolithographic condition therefor are properly selected tomake the accuracy of the formed position and shape of the coil conductor12 and the lower conductor 21 highly precisely. In addition, the coilconductor 12 and the lower conductor 21 are configured of a plurality ofconductive materials so as to perform selective etching, and a chemicalsolution for selective etching is used to etch the coil conductor 12 andthe lower conductor 21, whereby the accuracy of the formed position andshape of the coil conductor 12 and the lower conductor 21 can be madehighly precisely as well. It is also the same as the process steps offorming the upper conductor 23, the conductors 25 and 61, describedlater.

Subsequently, as shown in FIG. 3C, the dielectric film 31 having athickness of about 0.1 (μm) is formed throughout the surface. Forexample, for the material for forming the dielectric film 31, alumina,silicon nitride (Si₄N₃), silicon dioxide (SiO₂), tantalum oxide (Ta₂O₅),aluminium nitride (AlN) or magnesium oxide (MgO) are used. Thedielectric film 31 is formed to cover throughout the top and the sidesurface of the lower conductor 21 and the coil conductor 12. The amountof deposition of the dielectric film 31 per time (deposition rate) isreduced or the apparatus configuration is considered, whereby theaccuracy of the surface thickness of the dielectric film 31 can be madehighly precisely.

Then, a photosensitive resin is applied to throughout the surface of thedielectric film 31 to form a photosensitive resin layer 82.Subsequently, as shown in FIG. 4A, the photosensitive resin layer 82 isexposed and developed, and an opening 82 a is formed in thephotosensitive resin layer 82 on the end part on the inner radius sideof the coil conductor 12. Then, the photosensitive resin layer 82 ispost baked (heat treated).

Subsequently, as shown in FIG. 4B, the dielectric film 31 exposed in theopening 82 a is removed by ashing to form the via opening 31 a in thedielectric film 31 in which the coil conductor 12 is exposed. At thistime, as necessary, the dielectric film 31 on the wafer cutting line(chip cutting surface), described later, may be removed at the sametime. When the dielectric film 31 is separated into pieces, the filmstress of the dielectric film 31 can be spread. Then, as shown in FIG.4C, the photosensitive resin layer 82 is removed.

Subsequently, as shown in FIG. 5A, for example, titanium (Ti) having afilm thickness of about 30 (nm) and copper (Cu) having a film thicknessof about 100 (nm) are in turn laminated on throughout the surface bysputtering to form a conductor 73 for forming the upper conductor. Theconductor 73 for forming the upper conductor may be formed by a filmdeposition process such as vapor deposition using a vacuum depositionapparatus.

Then, for example, a photosensitive resin having a thickness of about 3(μm) is applied to throughout the surface of the conductor 73 forforming the upper conductor by spin coating to form the photosensitiveresin layer 83. Subsequently, as shown in FIG. 5B, the photosensitiveresin layer 83 is exposed and developed, and the photosensitive resinlayer 83 is left only on the portion for the upper conductor 23 of theconductor 73 for forming the upper conductor.

Then, as shown in FIG. 5C, the conductor 73 for forming the upperconductor except the portion under the photosensitive resin layer 83 isremoved by dry etching or wet etching. Thus, the upper conductor (secondconductor) 23 configured of the conductor 73 for forming the upperconductor under the photosensitive resin layer 83 is formed. By theprocess steps described above, the capacitor element (capacitativeelement) 11 configured of the lower conductor 21, the dielectric film 31and the upper conductor 23 is formed.

Subsequently, as shown in FIG. 6A, the photosensitive resin layer 83 onthe upper conductor 23 is removed. Then, for example, a photosensitiveresin for semiconductors having a film thickness of about 7 to 8 (μm) isapplied to throughout the surface to form the insulating film 33.Subsequently, the insulating film 33 is pre baked. Then, as shown inFIG. 6B, the insulating film 33 is exposed and developed, and the viaopening 33 a is formed in the insulating film 33 in which the viaopening 31 a is exposed. In addition, the opening 33 b is formed in theinsulating film 33 on the upper conductor 23 at the same time in whichthe upper conductor 23 is partially exposed. Subsequently, theinsulating film 33 is post baked. Post bake causes the insulating film33 to be cured and shrunk, and the film thickness of the insulating film33 is about 5 (μm). In addition, as shown in FIG. 6B, the insulatingfilm 33 around the via opening 33 a and the opening 33 b are formed in atapered shape by cure and shrinkage. Laser, plasma ashing or wet etchingmay be used for working the openings 33 a and 33 b and grooves in theinsulating film 33.

Then, as shown in FIG. 6C, the conductor 25 and the conductor 61 areformed by the same method of forming the lower conductor 21 and the coilconductor 12. Although the drawing is omitted, the description is madein more detail. For example, Ti having a film thickness of about 30 (nm)and Cu having a film thickness of about 100 (nm) are in turn laminatedon throughout the surface by sputtering to form an underlying conductor.Subsequently, for example, a photosensitive resin having a thickness ofabout 8 (am) is applied to throughout the surface of the underlyingconductor by spin coating to form a photosensitive resin layer.

Then, the photosensitive resin layer is exposed and developed, and anopening in the same shape as that of the conductor 25 and the conductor61 is formed in the photosensitive resin layer.

Subsequently, a conductor of Cu having a thickness of about 8 (μm) isformed on the underlying conductor exposed in the opening byelectrolytic plating to form the conductor 25 b and the conductor 61 bhaving a thickness of about 8 (μm). Then, the photosensitive resin layeris removed.

Subsequently, as shown in FIG. 6C, the underlying conductor exposedaround and between the conductors 25 b and 61 b is removed by dryetching or wet etching to form the underlying conductor 25 a configuredof the underlying conductor under the conductor 25 b and the underlyingconductor 61 a configured of the underlying conductor under theconductor 61 b. Thus, the conductor (third conductor) 25 is formed inthe layered structure in which the underlying conductor 25 a and theconductor 25 b are laminated on the upper conductor 23 in the opening 33b and on the insulating film 33, and the conductor 61 is formed in thelayered structure in which the underlying conductor 61 a and theconductor 61 b are laminated in the via openings 31 a and 33 a and onthe insulating film 33.

By the process steps described above, the inductor element 13 configuredof the coil conductor 12 and the conductor 61 is formed. Then, as shownin FIG. 7, an alumina protective film 54 having a thickness of about 30(μm) is formed throughout the surface.

Subsequently, the wafer is cut along a predetermined cutting line, and aplurality of the electronic components 1 formed on the wafer isseparated into a chip shape for every device forming area. Then,although the drawing is omitted, external electrodes electricallyconnected to the conductor 25 and the conductor 61 exposed in the cutsurface are formed on the cut surface. Before or after the externalelectrodes are formed, corners are chamfered as necessary to completethe electronic component 1.

In accordance with the method of fabricating the electronic component 1according to the embodiment, as shown in FIGS. 6B and 6C, at the timewhen the conductor 25 and the conductor 61 are formed, the coilconductor 12, the lower conductor 21, the upper conductor 23 and thedielectric film 31 are covered with the insulating film 33. Thus, theinsulating film 33 functions as the protective film at the time when theconductor 25 and the conductor 61 are formed, and the conductors 12, 21and 23 and the dielectric film 31 do not suffer from damages caused byetching of the underlying conductor, for example. Therefore, differentfrom the thin film capacitor 811 disclosed in Patent Reference 2, sincethe upper conductor 23 is not etched at the time when the conductor 25and the conductor 61 are formed, the upper conductor 23 can be formed ina desired shape and dimensions, and the electrode area of the capacitorelement 11 can be made highly accurately, whereby the capacitance valueof the capacitor element 11 can be made highly precisely. In addition,since the side surfaces of the lower conductor 21 and the dielectricfilm 31 and so on are not etched at the time when the conductor 25 andthe conductor 61 are formed, a short circuit between the lower conductor21 and the upper conductor 23 can be prevented.

In addition, since the dielectric film 31 is formed to cover throughoutthe top and the side surface of the lower conductor 21 and the coilconductor 12 and functions as the protective film, electromigration doesnot occur even though an organic material is used for the insulatingfilm 33. Therefore, the process steps of forming the conductor of Ni orTi on the lower conductor 21 and the coil conductor 12 are eliminated.In addition, the lower conductor 21 and the coil conductor 12 of thecapacitor element 11 are formed in the same process steps at the sametime, and the conductor 25 and the conductor 61 are formed in the sameprocess steps at the same time. Therefore, the number of the fabricationprocess steps can be reduced, and the electronic component 1 can befabricated at low costs. In addition, since the insulating properties ofthe insulating film 33 can be secured, the yield of the electroniccomponent 1 is enhanced, and it is intended to provide the electroniccomponent 1 at low costs.

Electronic components according to exemplary modifications of theembodiment will be described with reference to FIGS. 8A to 11B. In thedescription below, components that exert the same function and operationas those of the first embodiment are designated the same numerals andsigns, omitting the detailed descriptions.

Exemplary Modification 1

First, an electronic component 2 according to an exemplary modification1 of the embodiment will be described with reference to FIGS. 8A and 8B.FIG. 8A shows a plan view depicting the electronic component 2 accordingto the exemplary modification showing only a conductor part, and FIG. 8Bshows an equivalent circuit of the electronic component 2. As shown inFIG. 8A, in the electronic component 2, the conductor of the end part onthe outer radius side of a coil conductor 12 in a spiral shape partiallyfunctions as a lower conductor 21 of a capacitor element 11. As shown inFIG. 8B, the capacitor element 11 is serially connected to an inductorelement 13 to configure a series resonant circuit. A conductor 61 and aconductor 25 are current carrying terminals. The configuration of theelectronic component 2 except the points above is the same as that ofthe electronic component 1, omitting the descriptions.

Exemplary Modification 2

Subsequently, an electronic component 3 according to an exemplarymodification 2 of the embodiment will be described with reference toFIGS. 9A and 9B. FIG. 9A shows a plan view depicting the electroniccomponent 3 according to the exemplary modification, showing only aconductor part, and FIG. 9B shows an equivalent circuit diagramdepicting the electronic component 3. As shown in FIG. 9A, an inductorelement 13 has a coil conductor 12 in a spiral shape, and a rectangularconductor 61 which is connected at the end part on the inner radius sideof the coil conductor 12 and laterally extended in the drawing. Acapacitor element 11 has a rectangular lower conductor 21 which isformed in one piece with the coil conductor 12, connected at the endpart on the outer radius side of the coil conductor 12 and laterallyextended in the drawing, a dielectric film 31 which is formed on thelower conductor 21, and an upper conductor 23 which is formed on thedielectric film 31. To the upper conductor 23, an L-shaped conductor 25is connected which is formed in one piece with a conductor 61 andarranged on the lower conductor 21 as faced thereto. As shown in FIG.9B, the capacitor element 11 and the inductor element 13 are connectedin parallel to configure a parallel resonant circuit. The conductor 25is electrically connected to the conductor 61. The conductor 61 and thelower conductor 21 are current carrying terminals. The configuration ofthe electronic component 3 except the points above is the same as thatof the electronic component 1, omitting the descriptions.

Exemplary Modification 3

Then, an electronic component 4 according to an exemplary modification 3of the embodiment will be described with reference to FIGS. 10A and 10B.FIG. 10A shows a plan view depicting the electronic component 4according to the exemplary modification, showing only a conductor part,and FIG. 10B shows an equivalent circuit diagram depicting theelectronic component 4. As shown in FIG. 10A, an inductor element 13 hasa coil conductor 12 in a spiral shape, and a rectangular conductor 61which is connected at the end part on the inner radius side of the coilconductor 12 and laterally extended in the drawing. A capacitor element11 has a rectangular lower conductor 21 which is formed in one piecewith the coil conductor 12, connected at the end part on the outerradius side of the coil conductor 12 and laterally extended in thedrawing, a dielectric film 31 which is formed on the lower conductor 21,and an upper conductor 23 which is formed on the dielectric film 31. Tothe upper conductor 23, a rectangular conductor 25 is connected which isarranged on the lower conductor 21 as faced thereto. As shown in FIG.10B, the inductor element 13 and the capacitor element 11 configure alow pass filter. The conductor 61 is a terminal on the input side. Inaddition, a lead conductor 62 which is lead out near the end part on theouter radius side of the coil conductor 12 is a terminal on the outputside. The conductor 25 is a terminal for connecting ground. Theconfiguration of the electronic component 4 except the points above isthe same as that of the electronic component 1, omitting thedescriptions.

Exemplary Modification 4

Next, an electronic component 5 according to an exemplary modification 4of the embodiment will be described with reference to FIGS. 11A and 11B.FIG. 11A shows a plan view depicting the electronic component 5according to the exemplary modification, showing only a conductor part,and FIG. 11B shows an equivalent circuit diagram depicting theelectronic component 5. As shown in FIG. 11A, an inductor element 13 hasa coil conductor 12 in a spiral shape, and a rectangular conductor 61which is connected at the end part on the inner radius side of the coilconductor 12 and vertically extended in the drawing. A capacitor element11 has a rectangular lower conductor 21 which is formed in one piecewith the coil conductor 12, connected at the end part on the outerradius side of the coil conductor 12 and laterally extended in thedrawing, a dielectric film 31 which is formed on the lower conductor 21,and an upper conductor 23 which is formed on the dielectric film 31. Tothe upper conductor 23, a rectangular conductor 25 is connected which isarranged on the lower conductor 21 as faced thereto. As shown in FIG.11B, the inductor element 13 and the capacitor element 11 configure ahigh pass filter. The conductor 25 is a terminal on the input side, andthe lower conductor 21 is a terminal on the output side. The conductor61 is a terminal for connecting ground. The configuration of theelectronic component 5 except the points above is the same as that ofthe electronic component 1, omitting the descriptions.

Second Embodiment

An electronic component and a method of fabricating the same accordingto a second embodiment of the invention will be described with referenceto FIGS. 12 to 14. First, an electronic component 101 according to theembodiment will be described with reference to FIG. 12. FIG. 12 shows across section depicting the electronic component 101 according to theembodiment.

The electronic component 101 according to the embodiment ischaracterized in that the surface of an insulating film 33 is flatalmost throughout the surface of a substrate 51 as compared with theelectronic component 1 according to the first embodiment. Theconfiguration of the electronic component 101 is the same as that of theelectronic component 1 except that the insulating film 33 is flat almostthroughout the surface of the substrate 51, omitting the descriptions.

In the electronic component 101 according to the embodiment, since thesurface of the insulating film 33 is flat almost throughout the surfaceof the substrate 51 and the thickness distribution of the insulatingfilm 33 is uniform, the distance between a lower conductor 21 and aconductor 25 which is formed on the insulating film 33 is constantalmost throughout the surface of the substrate 51. Therefore, ascompared with the electronic component 1 according to the firstembodiment, electromagnetic coupling such as parasitic inductance andstray capacitance (parasitic capacitance) that occur between the lowerconductor 21 and the conductor 25 which is formed on the insulating film33 is more reduced. Accordingly, the capacitance value of a capacitorelement 11 can be obtained more highly precisely. In addition, ascompared with the electronic component 1, since ESR and ESL can be morereduced, the electric characteristics of the capacitor element 11 areimproved.

In addition, as compared with the electronic component 1, since thethickness distribution of the insulating film 33 is uniform, insulationresistance between the lower conductor 21 and the conductor 25 can bemaintained much higher, and the breakdown limit of the withstand voltagevalue and the insulating properties of the electronic component 101 aremore improved.

In addition, since the surface of the insulating film 33 is flat almostthroughout the surface of the substrate 51, the distance between thecoil conductor 12 and a conductor 61 which is formed on the insulatingfilm 33 is constant almost throughout the surface of the substrate 51.Therefore, as compared with the electronic component 1, straycapacitance that occurs between the coil conductor 12 and the conductor61 which is formed on the insulating film 33 is more reduced. Inaddition, since the surface of the insulating film 33 is flat almostthroughout the surface of the substrate 51, as compared with theelectronic component 1, the electronic component 101 can be more easilyformed in a super multilayer form. Moreover, the electronic component101 according to the embodiment can obtain the same advantages as thoseof the electronic component 1 according to the first embodiment.

A method of fabricating the electronic component 101 according to theembodiment will be described with reference to FIGS. 13A to 14. Althougha large number of the electronic components 101 are formed on a wafer atthe same time, FIGS. 13A to 14 show the device forming area of a singleelectronic component 101. FIGS. 13A to 14 show cross sections depictingthe fabrication process steps of the electronic component 101 accordingto the embodiment.

First, as shown in FIG. 13A, by the same fabricating method of theelectronic component 1 according to the first embodiment, a coilconductor 12, a lower conductor (first conductor) 21 and a dielectricfilm 31 are formed on a planarized layer 52 of a substrate 51, a viaopening 31 a is formed in the dielectric film 31, and an upper conductor(second conductor) 23 is formed on the dielectric film 31 (see FIGS. 2Ato 6A).

Then, for example, a photosensitive resin for semiconductors is appliedto throughout the surface to form an insulating film 33 having a filmthickness of about 7 to 8 (μm). Subsequently, the insulating film 33 ispre baked. Then, the insulating film 33 is exposed and developed, and avia opening 33 a is formed in the insulating film 33 in which the viaopening 31 a is exposed. Moreover, the opening 33 b is formed in theinsulating film 33 on the upper conductor 23 at the same time in whichthe upper conductor 23 is partially exposed. Subsequently, theinsulating film 33 is post baked. Then, as shown in FIG. 13B, thesurface of the insulating film 33 is polished by CMP.

Subsequently, as shown in FIG. 13C, the conductor 25 and the conductor61 are formed by the same fabricating method of the electronic component1 according to the first embodiment (see FIG. 6C). Then, as shown inFIG. 14, the alumina protective film 54 having a thickness of about 30(μm) is formed throughout the surface.

Subsequently, the wafer is cut along a predetermined cutting line, aplurality of the electronic components 101 which is formed on the waferis separated into a chip shape for every device forming area. Althoughthe drawing is omitted, external electrodes electrically connected tothe conductor 25 and the conductor 61 exposed in the cut surface arethen formed on the cut surface. Before or after the external electrodesare formed, corners are chamfered as necessary to complete theelectronic component 101. In accordance with the method of fabricatingthe electronic component 101 according to the embodiment, the sameadvantages as those of the method of fabricating the electroniccomponent 1 according to the first embodiment can be obtained.

Third Embodiment

An electronic component and a method of fabricating the same accordingto a third embodiment of the invention will be described with referenceto FIG. 15. FIG. 15 shows a cross section depicting an electroniccomponent 201 according to the embodiment. In addition, in FIG. 15 andthe drawings after that, the tapered shape of an insulating film 33around openings 33 a and 33 b is omitted.

The electronic component 201 according to the embodiment ischaracterized in that the surfaces of conductors 25 and 61 are flatalmost throughout the surface of a substrate 51 as compared with theelectronic component 101 according to the second embodiment. Theconfiguration of the electronic component 201 is the same as that of theelectronic component 101 except that the surfaces of the conductors 25and 61 are flat almost throughout the surface of the substrate 51,omitting the descriptions.

In the electronic component 201 according to the embodiment, since thesurfaces of the conductors 25 and 61 are flat almost throughout thesurface of the substrate 51, as compared with the electronic components1 and 101, the electronic component 201 can be more easily formed in asuper multilayer form. For example, a dielectric film 31, an upperconductor 23 and the conductor 25 are alternately laminated on aconductor 25, whereby a capacitor element 11 of high capacitance can beobtained.

In addition, the area of the upper conductor to be formed on theconductor 25 may be formed larger than the area of the upper conductor23, and the electrode area of the capacitor element to be laminated onthe capacitor element 11 may be formed larger than the electrode area ofthe capacitor element 11. As described above, in the capacitor elementin which a plurality of capacitor elements is laminated, each of theelectrode areas of the capacitor elements can be formed larger than thecapacitor element in the lower layer. Therefore, a plurality of thecapacitor elements is further laminated on the capacitor element 11,whereby a layered capacitor element of higher capacitance can beobtained. In addition, in the capacitor element in which a plurality ofcapacitor elements is laminated, the electrode area of the capacitorelement in each layer can be laid out freely. In addition, theelectronic component 201 according to the embodiment can obtain the sameadvantages as those of the electronic component 101 according to thesecond embodiment.

A method of fabricating the electronic component 201 according to theembodiment will be described briefly. The method of fabricating theelectronic component 201 is the same as the method of fabricating theelectronic component 101 shown in FIGS. 13A to 14 except the processsteps forming the conductor 25 and the conductor 61.

Although the drawing is omitted, the process steps forming the conductor25 and the conductor 61 will be described. For example, Ti having a filmthickness of about 30 nm and Cu having a film thickness of about 100 nmare in turn laminated on throughout the surface by sputtering to form anunderlying conductor. Then, for example, a photosensitive resin having athickness of about 8 μm is applied to throughout the surface of theunderlying conductor by spin coating to form a photosensitive resinlayer.

Subsequently, the photosensitive resin layer is exposed and developed,and an opening in the same shape as that of the conductor 25 and theconductor 61 is formed in the photosensitive resin layer.

Then, a conductor of Cu having a thickness of 9 to 10 (μm) is formed onthe underlying conductor exposed in the opening by electrolytic plating,and the surface of the conductor is polished by CMP polishing to form aconductor 25 b and a conductor 61 b having a thickness of about 8 (μm).Subsequently, the photosensitive resin layer is developed and removed.

Then, the underlying conductor exposed around and between the conductors25 b and 61 b is removed by dry etching or wet etching to form anunderlying conductor 25 a configured of the underlying conductor underthe conductor 25 b and an underlying conductor 61 a configured of theunderlying conductor under the conductor 61 b. Thus, the conductor(third conductor) 25 is formed in the layered structure in which theunderlying conductor 25 a and the conductor 25 b are laminated, and theconductor 61 is formed in the layered structure in which the underlyingconductor 61 a and the conductor 61 b are laminated. In accordance withthe method of fabricating the electronic component 201 according to theembodiment, the same advantages as those of the method of fabricatingthe electronic component 1 according to the first embodiment can beobtained.

Fourth Embodiment

An electronic component according to a fourth embodiment of theinvention will be described with reference to FIG. 16. FIG. 16 shows across section depicting an electronic component 301 according to theembodiment.

The electronic component 301 according to the embodiment ischaracterized in that a conductor 25 is configured of two layers, acolumn shaped conductor 27 which is formed in an opening 33 b and aconductor 29 which is formed on an insulating film 33 from the upperpart of the opening 33 b to the rim part on the short side of theelectronic component 1, and a conductor 61 is configured of two layers,a via conductor 63 which is formed in via openings 31 a and 33 a and aconductor 65 which is formed in a slim rectangular shape from the upperpart of the via opening 33 a to the rim part on the short side of theelectronic component 301 as compared with the electronic component 201according to the second embodiment.

Underlying conductors 27 a and 63 a of the column shaped conductor 27and the via conductor 63 are formed on the bottom and the side part ofeach of the conductors. On the underlying conductors 27 a and 63 a,conductors 27 b and 63 b are formed. The conductor 29 is configured ofan underlying conductor 29 a which is formed on the column shapedconductor 27 and the insulating film 33 and an conductor 29 b which isformed on the underlying conductor 29 a. The conductor 65 is configuredof an underlying conductor 65 a which is formed on the via conductor 63and the insulating film 33 and a conductor 65 b which is formed on theunderlying conductor 65 a.

The configuration of the electronic component 301 is the same as that ofthe electronic component 201 except the points described above, omittingthe descriptions. The electronic component 301 according to theembodiment can obtain the same advantages as those of the electroniccomponent 201 according to the third embodiment.

Fifth Embodiment

An electronic component and a method of fabricating the same accordingto a fifth embodiment of the invention will be described with referenceto FIGS. 17 to 22C. FIG. 17 shows a cross section depicting anelectronic component 401 according to the embodiment.

The electronic component 401 according to the embodiment ischaracterized in that a dielectric film 31 is flat almost throughout thesubstrate surface of a substrate 51 as compared with the electroniccomponent 201 according to the third embodiment. An insulating film 135is formed around and in a space between a lower conductor 21 and a coilconductor 12. For example, the insulating film 135 is formed of aphotosensitive resin such as photosensitive polyimide. The filmthickness of the insulating film 135 is almost equal to the thickness ofthe lower conductor 21 and the coil conductor 12, and the surfaces ofthe lower conductor 21, the coil conductor 12 and the insulating film135 are formed smoothly. The dielectric film 31 is formed flat overalmost throughout the surfaces of the lower conductor 21, the coilconductor 12 and the insulating film 135. The configuration of theelectronic component 401 is the same as that of the electronic component201 except that the surfaces of the lower conductor 21, the coilconductor 12 and the insulating film 135 are formed flat and that thedielectric film 31 is flat almost throughout the substrate surface ofthe substrate 51, omitting the descriptions.

In the electronic component 401 according to the embodiment, theinsulating film 135 is formed in the same layer as the lower conductor21 and the coil conductor 12 to have a flat surface. The dielectric film31 is formed on the flat surface. Therefore, even though the dielectricfilm 31 is made thin, the film thickness of the dielectric film 31 isflat even at the end part of the lower conductor 21, and the insulatingproperties to the upper conductor 23 and the lower conductor 21 can beobtained. Accordingly, as compared with the electronic component 201according to the third embodiment, the electronic component 401 canimprove the breakdown limit of the withstand voltage value of theelectronic component 1. Moreover, the electronic component 401 accordingto the embodiment can obtain the same advantages as those of theelectronic component 201 according to the third embodiment.

A method of fabricating the electronic component 401 according to theembodiment will be described with reference to FIGS. 18A to 22C.Although a plurality of the electronic components 401 is formed on awafer at the same time, FIG. 18A to 22C show the device forming area ofa single electronic component 401. FIGS. 18A to 22C show cross sectionsdepicting the fabrication process steps of the electronic component 401according to the embodiment.

First, as shown in FIG. 18A, the coil conductor 12 and the lowerconductor (first conductor) 21 are formed on a planarized layer 52 ofthe substrate 51 by the same method of fabricating the electroniccomponent 1 according to the first embodiment (see FIGS. 2A to 3B).

Then, as shown in FIG. 18B, for example, a photosensitive resin such aspolyimide is applied to throughout the surface to form the insulatingfilm 135. Subsequently, the insulating film 135 is post baked. Then, asshown in FIG. 19A, the surface of the insulating film 135 is polished byCMP until the surfaces of the lower conductor 21 and the coil conductor12 are exposed, and the lower conductor 21, the coil conductor 12 andthe insulating film 135 are formed to have a thickness of about 8 μm. Inthis manner, the surfaces of the lower conductor 21, the coil conductor12 and the insulating film 135 are planarized.

Subsequently, as shown in FIG. 19B, the dielectric film 31 having athickness of about 0.1 μm is formed throughout the surface. For thematerial for forming the dielectric film 31, for example, alumina,silicon nitride (Si₄N₃), silicon dioxide (SiO₂), tantalum oxide (Ta₂O₅),aluminium nitride (AlN) or magnesium oxide (MgO) are used. Since thesurfaces of the lower conductor 21, the coil conductor 12 and theinsulating film 135 are flat, the dielectric film 31 is formed flat tocover throughout the top of the lower conductor 21, the coil conductor12 and the insulating film 135.

Then, a photosensitive resin is applied to throughout the surface of thedielectric film 31 to form a photosensitive resin layer 82.Subsequently, as shown in FIG. 19C, the photosensitive resin layer 82 isexposed and developed, and an opening 82 a is formed in thephotosensitive resin layer 82 on the end part on the inner radius sideof the coil conductor 12. After that, the photosensitive resin layer 82is post baked (heat treated).

Then, as shown in FIG. 20A, the dielectric film 31 exposed in theopening 82 a is removed by ashing to form a via opening 31 a in thedielectric film 31 in which the coil conductor 12 is exposed. At thistime, as necessary, the dielectric film 31 on the wafer cutting line(chip cutting surface), described later, may be removed at the sametime. The dielectric film 31 is separated into pieces, and the filmstress owed by the dielectric film 31 can be spread. After that, asshown in FIG. 20B, the photosensitive resin layer 82 is removed.

Subsequently, as shown in FIG. 20C, for example, titanium (Ti) having afilm thickness of about 30 (nm) and copper (Cu) having a film thicknessof about 100 (nm) are in turn laminated on throughout the surface bysputtering to form a conductor 73 for forming the upper conductor. Theconductor 73 for forming the upper conductor may be formed by a filmdeposition process such as vapor deposition using a vacuum depositionapparatus.

Then, for example, a photosensitive resin having a thickness of about 3(μm) is applied to throughout the surface of the conductor 73 forforming the upper conductor by spin coating to form a photosensitiveresin layer 83. Subsequently, as shown in FIG. 21A, the photosensitiveresin layer 83 is exposed and developed, and the photosensitive resinlayer 83 is left only on the portion to be the upper conductor 23 forthe conductor 73 for forming the upper conductor.

Then, as shown in FIG. 21B, the conductor 73 for forming the upperconductor except the portion under the photosensitive resin layer 83 isremoved by dry etching or wet etching. Thus, the upper conductor (secondconductor) 23 configured of the conductor 73 for forming the upperconductor under the photosensitive resin layer 83 is formed. By theprocess steps described above, the capacitor element (capacitativeelement) 11 is formed which is configured of the lower conductor 21, thedielectric film 31 and the upper conductor 23.

Subsequently, as shown in FIG. 21C, the photosensitive resin layer 83 onthe upper conductor 23 is removed. Then, for example, a photosensitiveresin for semiconductors is applied to throughout the surface to form aninsulating film 33 having a film thickness of about 7 to 8 (μm).Subsequently, the insulating film 33 is pre baked. Then, as shown inFIG. 22A, the insulating film 33 is exposed and developed, and a viaopening 33 a is formed in the insulating film 33 in which the viaopening 31 a is exposed. Moreover, the opening 33 b is formed in theinsulating film 33 on the upper conductor 23 at the same time in whichthe upper conductor 23 is partially exposed. Subsequently, theinsulating film 33 is post baked. Then, the surface of the insulatingfilm 33 is polished by CMP polishing.

Subsequently, as shown in FIG. 22B, the conductor 25 and the conductor61 are formed by the same method of forming the lower conductor 21 andthe coil conductor 12. Although the drawing is omitted, the descriptionis made in more detail. For example, Ti having a film thickness of about30 (nm) and Cu having a film thickness of about 100 (nm) are in turnlaminated on throughout the surface by sputtering to form an underlyingconductor. Then, for example, a photosensitive resin having a thicknessof about 8 (μm) is applied to throughout the surface of the underlyingconductor by spin coating to form a photosensitive resin layer.

Subsequently, the photosensitive resin layer is exposed and developed,and an opening in the same shape as that of the conductor 25 and theconductor 61 is formed in the photosensitive resin layer.

Then, a conductor of Cu having a thickness of 9 to 10 (μm) is formed onthe underlying conductor exposed in the opening by electrolytic plating,and the surface of the conductor is then polished by CMP polishing toform a conductor 25 b and the conductor 61 b having a thickness of about8 (μm) Subsequently, the photosensitive resin layer is removed.

Then, as shown in FIG. 22B, the underlying conductor exposed around andbetween the conductors 25 b and 61 b is removed by dry etching or wetetching to form the underlying conductor 25 a which is configured of theunderlying conductor under the conductor 25 b and the underlyingconductor 61 a configured of the underlying conductor under theconductor 61 b. Thus, the conductor (the third conductor) 25 is formedin the layered structure in which the underlying conductor 25 a and theconductor 25 b are laminated on the upper conductor 23 and theinsulating film 33 in the opening 33 b, and the conductor 61 is formedin the layered structure in which the underlying conductor 61 a and theconductor 61 b are laminated in the via openings 31 a and 33 a and onthe insulating film 33.

By the process steps described above, the inductor element 13 configuredof the coil conductor 12 and the conductor 61 is formed. Subsequently,as shown in FIG. 22C, the alumina protective film 54 having a thicknessof about 30 (μm) is formed throughout the surface.

After that, the wafer is cut along a predetermined cutting line, and aplurality of the electronic components 401 which is formed on the waferis separated into a chip shape for every device forming area. Then,although the drawing is omitted, external electrodes electricallyconnected to the conductor 25 and the conductor 61 exposed in the cutsurface are formed on the cut surface. Before or after the externalelectrodes are formed, corners are chamfered as necessary to completethe electronic component 401. In accordance with the method offabricating the electronic component 401 according to the embodiment,the same advantages as those of the method of fabricating the electroniccomponent 1 according to the first embodiment can be obtained.

Sixth Embodiment

An electronic component and a method of fabricating the same accordingto a sixth embodiment of the invention will be described with referenceto FIGS. 23 to 28C. FIG. 23 shows a cross section depicting anelectronic component 501 according to the embodiment.

The electronic component 501 according to the embodiment ischaracterized in that conductors 12, 21, 25 and 61 are formed bydamascene as compared with the coil conductor 12, the lower conductor 21and the conductors 25 and 61 of the electronic component 401 accordingto the fifth embodiment are formed by the semi-additive process(deposition). Underlying conductors 12 a and 21 a of the coil conductor12 and the lower conductor 21 are formed on the bottom and the side partof each of the conductors. The configuration of the electronic component501 is the same as that of the electronic component 401 except that theconductors 12, 21, 25 and 61 are formed by damascene in the structure inwhich the underlying conductors 12 a and 21 a are provided on the sideparts of the coil conductor 12 and the lower conductor 21, omitting thedetailed descriptions. The electronic component 501 according to theembodiment can obtain the same advantages as those of the electroniccomponent 401 according to the fifth embodiment.

A method of fabricating the electronic component 501 according to theembodiment will be described with reference to FIGS. 24A to 28C.Although a plurality of the electronic components 501 is formed on awafer at the same time, FIGS. 24A to 28C show the device forming area ofa single electronic component 501. FIGS. 24A to 28C show cross sectionsdepicting the fabrication process steps of the electronic component 501according to the embodiment.

In the embodiment, a planarized substrate 51 is used as a substrate.First, the surface of alumina formed on throughout the surface of thesubstrate 51 formed of alumina (Al₂O₃) is polished by CMP(chemical-mechanical polishing) to form a planarized layer 52.

Subsequently, for example, a photosensitive resin such as polyimide isapplied to throughout the surface to form an insulating film 135. Then,the insulating film 135 is pre baked. Then, as shown in FIG. 24A, theinsulating film 135 is exposed and developed, and an opening 135 a in arectangular shape and an opening 135 b in a spiral shape are formed inthe insulating film 135 when the substrate 51 is seen in the normaldirection thereof. The end part on the outer radius side of the opening135 b is connected to the opening 135 a. Subsequently, the insulatingfilm 135 is post baked.

Then, as shown in FIG. 24B, for example, titanium (Ti) having a filmthickness of about 30 nm and copper (Cu) having a film thickness ofabout 100 nm are in turn laminated on throughout the surface bysputtering to form an underlying conductor 71. The underlying conductor71 is also formed on the side part and the bottom of the openings 135 aand 135 b.

Subsequently, as shown in FIG. 24C, a conductor 72 of Cu having athickness of 9 to 10 μm is formed on the underlying conductor 71 byelectrolytic plating. Then, as shown in FIG. 25A, all the surface ispolished by CMP polishing until the insulating film 135 is exposed toform a conductor pattern to form a lower conductor (first conductor) 21having a thickness of about 8 μm in the opening 135 a, and the coilconductor 12 having the same thickness is formed in the opening 135 b atthe same time. The lower conductor 21 is configured of an underlyingconductor 21 a formed of the underlying conductor 71 and a conductor 21b formed of the conductor 72. The coil conductor 12 is configured of anunderlying conductor 12 a formed of the underlying conductor 71 and aconductor 12 b formed of the conductor 72.

The conductor 25 and the conductor 61, described later, are formed bythe same method of the coil conductor 12 and the lower conductor 21. Inaddition, the wiring layer for the coil conductor 12 and the conductor61, described later, may be the wiring layer for any one of the wiringlayers of the lower conductor 21 and the upper conductor 23, which canbe arranged freely in consideration of the ease of the wiring design andthe electric characteristics and shape of the inductor element 13.

Subsequently, as shown in FIG. 25B, a dielectric film 31 having athickness of about 0.1 μm is formed throughout the surface. For thematerial for forming the dielectric film 31, for example, alumina,silicon nitride (Si₄N₃), silicon dioxide (SiO₂), tantalum oxide (Ta₂O₅),aluminium nitride (AlN) or magnesium oxide (MgO) are used. Since thesurfaces of the lower conductor 21, the coil conductor 12 and theinsulating film 135 are flat, the dielectric film 31 is formed flat tocover throughout the top of the lower conductor 21, the coil conductor12 and the insulating film 135.

Then, a photosensitive resin is applied to throughout the surface of thedielectric film 31 to form a photosensitive resin layer 82.Subsequently, as shown in FIG. 25C, the photosensitive resin layer 82 isexposed and developed, and an opening 82 a is formed in thephotosensitive resin layer 82 on the end part on the inner radius sideof the coil conductor 12. Then, the photosensitive resin layer 82 ispost baked (heat treated).

Then, as shown in FIG. 26A, the dielectric film 31 exposed in theopening 82 a is removed by ashing to form a via opening 31 a in thedielectric film 31 in which the coil conductor 12 is exposed. At thistime, as necessary, the dielectric film 31 on the wafer cutting line(chip cutting line), described later, may be removed at the same time.When the dielectric film 31 is separated into pieces, the film stressowed by the dielectric film 31 can be spread. Subsequently, as shown inFIG. 26B, the photosensitive resin layer 82 is removed.

Then, as shown in FIG. 26C, for example, titanium (Ti) having a filmthickness of about 30 (nm) and copper (Cu) having a film thickness ofabout 100 (nm) are in turn laminated on throughout the surface bysputtering to form a conductor 73 for forming the upper conductor. Theconductor 73 for forming the upper conductor may be formed by a filmdeposition process such as vapor deposition using a vacuum depositionapparatus.

Subsequently, for example, a photosensitive resin having a thickness ofabout 3 (μm) is applied to throughout the surface of the conductor 73for forming the upper conductor by spin coating to form a photosensitiveresin layer 83. Then, as shown in FIG. 27A, the photosensitive resinlayer 83 is exposed and developed, and the photosensitive resin layer 83is left only on the portion to be the upper conductor 23 for theconductor 73 for forming the upper conductor.

Subsequently, as shown in FIG. 27B, the conductor 73 for forming theupper conductor except the portion under the photosensitive resin layer83 is removed by dry etching or wet etching. Thus, the upper conductor(second conductor) 23 configured of the conductor 73 for forming theupper conductor under the photosensitive resin layer 83 is formed. Bythe process steps described above, the capacitor element (capacitativeelement) 11 configured of the lower conductor 21, the dielectric film 31and the upper conductor 23 is formed.

Then, as shown in FIG. 27C, the photosensitive resin layer 83 on theupper conductor 23 is removed. Subsequently, for example, aphotosensitive resin for semiconductors is applied to throughout thesurface to form an insulating film 33 having a film thickness of about 7to 8 (μm). Then, the insulating film 33 is pre baked. Subsequently, asshown in FIG. 28A, the insulating film 33 is exposed and developed, anda via opening 33 a is formed in the insulating film 33 in which the viaopening 31 a is exposed. Moreover, the opening 33 b is formed in theinsulating film 33 on the upper conductor 23 at the same time in whichthe upper conductor 23 is partially exposed. Then, the insulating film33 is post baked. Subsequently, the surface of the insulating film 33 ispolished by CMP polishing. For processing the opening 33 b of theinsulating film 33 and groves, laser, plasma ashing or wet etching maybe used.

Then, as shown in FIG. 28B, the conductor 25 and the conductor 61 areformed by the same method of forming the lower conductor 21 and the coilconductor 12. Although the drawing is omitted, the description is madein more detail. For example, a photosensitive resin having a thicknessof about 8 μm is applied to throughout the surface by spin coating toform a photosensitive resin layer. Then, the photosensitive resin layeris exposed and developed, and an opening in the same shape as that ofthe conductor 25 and the conductor 61 is formed in the photosensitiveresin layer. Subsequently, for example, Ti having a film thickness ofabout 30 nm and Cu having a film thickness of about 100 nm are in turnlaminated on throughout the surface by sputtering to form an underlyingconductor.

Then, a conductor of Cu having a thickness of 9 to 10 μm is formed onthe underlying conductor by electrolytic plating. Subsequently, theentire surface is polished by CMP polishing until the photosensitiveresin layer is exposed to form a conductor pattern, and a conductor 25and a conductor 61 having a thickness of about 8 μm are formed. Theconductor 25 is configured of an underlying conductor 25 a and aconductor 25 b which is formed on the underlying conductor 25 a. Theconductor 61 is configured of an underlying conductor 61 a and aconductor 61 b which is formed on the underlying conductor 61 a. By theprocess steps described above, the inductor element 13 configured of thecoil conductor 12 and the conductor 61 is formed. Then, thephotosensitive resin layer is removed.

Subsequently, as shown in FIG. 28C, the alumina protective film 54having a thickness of about 30 (μm) is formed throughout the surface.Then, the wafer is cut along a predetermined cutting line, and aplurality of the electronic components 501 which is formed on the waferis separated into a chip shape for every device forming area.Subsequently, although the drawing is omitted, external electrodeselectrically connected to the conductor 25 and the conductor 61 exposedin the cut surface are formed on the cut surface. Before or after theexternal electrodes are formed, corners are chamfered as necessary tocomplete the electronic component 501. In accordance with the method offabricating the electronic component 501 according to the embodiment,the same advantages as those of the method of fabricating the electroniccomponent 1 according to the first embodiment can be obtained.

Seventh Embodiment

An electronic component according to the seventh embodiment of theinvention will be described with reference to FIG. 29. FIG. 29 shows across section depicting an electronic component 601 according to theembodiment.

The electronic component 601 according to the embodiment ischaracterized in that a conductor 25 is configured of two layers, acolumn shaped conductor 27 which is formed in an opening 33 b and aconductor 29 which is formed on an insulating film 33 from the upperpart of the opening 33 b to the rim part on the short side of anelectronic component 1, and a conductor 61 is configured of two layers,a via conductor 63 which is formed in the via openings 31 a and 33 a anda conductor 65 which is formed in a slim rectangular shape from theupper part of the via opening 33 a to the rim part on the short side ofthe electronic component 1 as compared with the electronic component 401according to the fifth embodiment.

Underlying conductors 27 a and 63 a of the column shaped conductor 27and the via conductor 63 are formed on the bottom and the side part ofeach of the conductors. Conductors 27 b and 63 b are formed on theunderlying conductors 27 a and 63 a. The conductor 29 is configured ofan underlying conductor 29 a which is formed on the column shapedconductor 27 and the insulating film 33 and a conductor 29 b which isformed on the underlying conductor 29 a. The conductor 65 is configuredof an underlying conductor 65 a which is formed on the via conductor 63and the insulating film 33 and a conductor 65 b which is formed on theunderlying conductor 65 a.

The configuration of the electronic component 601 is the same as that ofthe electronic component 401 except the points described above, omittingthe descriptions. The electronic component 601 according to theembodiment can obtain the same advantages as those of the electroniccomponent 401 according to the fifth embodiment.

Eighth Embodiment

An electronic component and a method of fabricating the same accordingto the eighth embodiment of the invention will be described withreference to FIGS. 30 to 34B. FIG. 30 shows a cross section depicting anelectronic component 701 according to the embodiment.

The electronic component 701 according to the embodiment ischaracterized in that a dielectric film 31 is formed only on a lowerconductor 21 as compared with the electronic component 401 according tothe fifth embodiment. The dielectric film 31 is formed only on theportion in which the lower conductor 21 and an upper conductor 23 arefaced to each other and the portion therearound when the substrate 51 isseen in the normal direction of the substrate surface. The configurationof the electronic component 701 is the same as that of the electroniccomponent 401 according to the fifth embodiment except that thedielectric film 31 is formed only on the lower conductor 21, omittingthe detailed descriptions.

In the electronic component 701 according to the embodiment, thedielectric film 31 is formed only on the lower conductor 21. Thus, ascompared with the electronic component 401, the electronic component 701can suppress internal stress and the variations in the dimensions of theelectronic component 701 to temperature. Therefore, the fluctuations inthe constant such as the capacitance value of the capacitor element 11due to temperature change can be suppressed. Accordingly, as comparedwith the electronic component 401 according to the fifth embodiment, theelectronic component 701 can improve the temperature characteristics ofthe capacitor element 11, and can obtain the capacitance value of thecapacitor element 11 more highly accurately. Furthermore, the electroniccomponent 701 according to the embodiment can obtain the same advantagesas those of the electronic component 401.

A method of fabricating the electronic component 701 according to theembodiment will be described with reference to FIGS. 31A to 34B.Although a plurality of the electronic components 701 is formed on awafer at the same time, FIGS. 31A to 34B show the device forming area ofa single electronic component 701. FIGS. 31A to 34B show cross sectionsdepicting the fabrication process steps of the electronic component 701according to the embodiment.

First, as shown in FIG. 31A, a coil conductor 12, a lower conductor(first conductor) 21 and an insulating film 135 are formed on aplanarized layer 52 of a substrate 51 to form a dielectric film 31throughout the surface by the same method of fabricating the electroniccomponent 401 according to the fifth embodiment (see FIGS. 2A to 3B andFIGS. 18A to 19B).

Then, a photosensitive resin is applied to throughout the surface of thedielectric film 31 to form a photosensitive resin layer 84. Then, asshown in FIG. 31B, the photosensitive resin layer 84 is exposed anddeveloped, and the photosensitive resin layer 84 is left only on thedielectric film 31 to be the electrode part of the lower conductor 21and the portion therearound. Subsequently, as shown in FIG. 31C, thedielectric film 31 except the portion under the photosensitive resinlayer 84 is removed by ashing. Thus, the dielectric film 31 is formedonly on the portion to be the electrode part of the lower conductor 21and the portion therearound. Then, as shown in FIG. 32A, thephotosensitive resin layer 84 is removed.

Subsequently, as shown in FIG. 32B, for example, titanium (Ti) having afilm thickness of about 30 (nm) and copper (Cu) having a film thicknessof about 100 (nm) are in turn laminated on throughout the surface bysputtering to form a conductor 73 for forming the upper conductor. Theconductor 73 for forming the upper conductor may be formed by a filmdeposition process such as vapor deposition using a vacuum depositionapparatus.

Then, for example, a photosensitive resin having a thickness of about 3(μm) is applied to throughout the surface of the conductor 73 forforming the upper conductor by spin coating to form a photosensitiveresin layer 83. Subsequently, as shown in FIG. 32C, the photosensitiveresin layer 83 is exposed and developed, and the photosensitive resinlayer 83 is left only on the conductor 73 for forming the upperconductor on the dielectric film 31 (the portion to be the upperconductor 23).

Then, as shown in FIG. 33A, the conductor 73 for forming the upperconductor except the portion under the photosensitive resin layer 83 isremoved by dry etching or wet etching. Thus, the upper conductor (secondconductor) 23 configured of the conductor 73 for forming the upperconductor under the photosensitive resin layer 83 is formed. By theprocess steps described above, the capacitor element (capacitativeelement) 11 configured of the lower conductor 21, the dielectric film 31and the upper conductor 23 is formed.

After that, as shown in FIG. 33B, the photosensitive resin layer 83 onthe upper conductor 23 is removed. Then, for example, a photosensitiveresin for semiconductors is applied to throughout the surface to form aninsulating film 33 having a film thickness of about 7 to 8 (μm).Subsequently, the insulating film 33 is pre baked. Then, as shown inFIG. 33C, the insulating film 33 is exposed and developed, and a viaopening 33 a is formed in the insulating film 33 in which the end parton the inner radius side of the coil conductor 12 is exposed. Moreover,the opening 33 b is formed in the insulating film 33 on the upperconductor 23 at the same time in which the upper conductor 23 ispartially exposed. Subsequently, the insulating film 33 is post baked.Then, the surface of the insulating film 33 is polished by CMPpolishing.

Subsequently, as shown in FIG. 34A, the conductor 25 and the conductor61 are formed by the same method of forming the lower conductor 21 andthe coil conductor 12. Although the drawing is omitted, the descriptionis made in more detail, for example, Ti having a film thickness of about30 (nm) and Cu having a film thickness of about 100 (nm) are in turnlaminated on throughout the surface by sputtering to form an underlyingconductor. Then, for example, a photosensitive resin having a thicknessof about 8 (μm) is applied to throughout the surface of the underlyingconductor by spin coating to form a photosensitive resin layer.

Subsequently, the photosensitive resin layer is exposed and developed,and an opening in the same shape as that of the conductor 25 and theconductor 61 is formed in the photosensitive resin layer.

Then, a conductor of Cu having a thickness of 9 to 10 (μm) is formed onthe underlying conductor exposed in the opening by electrolytic plating,and the surface of the conductor is then polished by CMP polishing toform a conductor 25 b and the conductor 61 b having a thickness of about8 (μm). Subsequently, the photosensitive resin layer is removed.

Then, as shown in FIG. 34A, the underlying conductor exposed around andbetween the conductors 25 b and 61 b is removed by dry etching or wetetching to form the underlying conductor 25 a which is configured of theunderlying conductor under the conductor 25 b and the underlyingconductor 61 a configured of the underlying conductor under theconductor 61 b. Thus, the conductor (third conductor) 25 is formed inthe layered structure in which the underlying conductor 25 a and theconductor 25 b are laminated on the upper conductor 23 in the opening 33b and on the insulating film 33, and the conductor 61 is formed in thelayered structure in which the underlying conductor 61 a and theconductor 61 b are laminated in the via opening 33 a and on theinsulating film 33.

By the process steps described above, the inductor element 13 configuredof the coil conductor 12 and the conductor 61 is formed. Subsequently,as shown in FIG. 34B, the alumina protective film 54 having a thicknessof about 30 (μm) is formed throughout the surface.

Then, the wafer is cut along a predetermined cutting line, and aplurality of the electronic components 701 which is formed on the waferis separated into a chip shape for every device forming area.Subsequently, although the drawing is omitted, external electrodeselectrically connected to the conductor 25 and the conductor 61 exposedin the cut surface are formed on the cut surface. Then, corners arechamfered as necessary to complete the electronic component 701. Inaccordance with the method of fabricating the electronic component 701according to the embodiment, the same advantages as those of the methodof fabricating the electronic component 1 according to the firstembodiment can be obtained.

The invention can be modified variously not limited to the embodiments.

In the embodiments, the electronic component containing only thecapacitor element 11 and the inductor element 13 is taken as an exampleas the electronic component, but the invention is not limited thereto.For example, the invention can be adapted to an RC composite electroniccomponent in which a resistance element is formed instead of theinductor element 13. In addition, the invention can be also adapted toan RLC composite electronic component having a resistance element inaddition to the capacitor element 11 and the inductor element 13. Inaddition, the invention can be also adapted to electronic componentscontaining an active component such as a transistor and a diode, notlimited to the electronic component containing only a passive componentas long as components are the electronic component containing thecapacitor element 11. Moreover, the invention can be also adapted tocircuits in which digital and analog elements are mixed as long ascomponents are the electronic component containing the capacitor element11. Moreover, a desired function can be achieved by a desired circuit inwhich any of LCR elements are combined in plural elements in order toobtain the desired function. Of course, such a circuit configuration maybe efficient that a distributed constant circuit is combined, notlimited to lumped constant, and they may be combined with semiconductordevices.

In addition, the material of the substrate 51 may be semiconductormaterials or low temperature co-fired ceramics (LTCC). In addition, theelectronic component 1 may be configured inside a circuit board.

In the first to eighth embodiments, the electronic component 1 havingthe capacitor element 11 in a single layer is taken and described as anexample, but the invention is not limited thereto. For example, theinvention can be also adapted to the electronic component 1 having alayered capacitor element in which the conductor and the dielectric film31 are in turn laminated repeatedly. When a layered capacitor element isformed, the capacitor elements 11 of the electronic component accordingto the first to eighth embodiments can be combined properly. Forexample, such schemes may be performed in which the capacitor elements11 according to the same embodiment are repeatedly laminated, thecapacitor element 11 according to one embodiment has the capacitorelement 11 according to another embodiment laminated thereon repeatedly,or the capacitor elements 11 according to two embodiments arealternately laminated.

In the embodiments, the electronic component in a rectangular sectionalshape of each of the conductors is taken as an example, but thesectional shape of each of the conductors may be a trapezoid, or aninverted trapezoid.

In the embodiments, the electronic component is taken as an example inwhich the conductor 25 has the column shaped conductor part formed inthe opening 33 b and the lead conductor part which is formed on theinsulating film 33 in order to connect the upper conductor 23 to theexternal electrode (not shown), but the invention is not limitedthereto. For example, the invention can be also adapted to a electroniccomponent in which the conductor 25 is configured only of a leadconductor part and the column shaped conductor part is formed on thelower conductor 21. In the electronic component, an upper conductor(second conductor) 23 which is thinner than the column shaped conductorpart is formed on the column shaped conductor part (third conductor), adielectric film 31 is formed on the upper conductor 23, and a leadconductor (first conductor) 25 configured only of the lead conductorpart is formed on the dielectric film 31. The conductor 25 is formedthicker than the upper conductor 23. In the electronic component, thecapacitor element (capacitative element) is configured of the upperconductor 23, the dielectric film 31 and the lead conductor part. In theelectronic component, the insulating film 33 is formed around the lowerconductor 21 and the column shaped conductor part. In addition, in theelectronic component, the upper conductor 23 is formed to cover thecolumn shaped conductor part when the substrate surface of a substrate51 is seen in the normal direction.

In the electronic component, since the upper conductor 23 is formedthinner, the upper conductor 23 in a highly accurate shape can beobtained. Thus, the area accuracy of the upper conductor 23 faced to theconductor 25 is highly accurate, and the electrode area of the capacitorelement can be formed highly precisely. Therefore, the capacitance valueof the capacitor element can be obtained highly precisely. In addition,when the insulating film 33 is thickened, the parasitic inductance andthe parasitic capacitance that occur between the lower conductor 21 andthe conductor 25 are decreased. Accordingly, the accuracy of thecapacitance value of the capacitor element 11 can be enhanced.

1. An electronic component comprising: a first conductor which is formedon a substrate; a dielectric film which is formed on the firstconductor, wherein the dielectric film is formed over almost throughoutan upper surface of the substrate so as to cover the first conductor; asecond conductor which is formed on the dielectric film disposed on thefirst conductor and thinner than the first conductor, wherein acapacitative element is configured of the first conductor, the secondconductor and the dielectric film; and an inductor element having a coilconductor formed in one piece with the first conductor and formed in asame layer as the first conductor and formed under the dielectric film,wherein an end part of the coil conductor functions as the firstconductor and the inductor element configures one of a resonant circuitand a filter circuit with the capacitative element, and the dielectricfilm is formed to cover throughout a top and a side surface of the firstconductor, and a top and a side surface of the coil conductor.
 2. Theelectronic component according to claim 1, wherein an electrode area ofthe capacitative element is defined by an area of the second conductor.3. The electronic component according to claim 1, wherein t1>t2 andx≦t2, where a thickness of the first conductor is t1, a thickness of thesecond conductor is t2, and a particle diameter of the second conductoris x.
 4. The electronic component according to claim 1, wherein anentire surface of the second conductor is flat.
 5. The electroniccomponent according to claim 1, further comprising an insulating filmwhich is formed on the second conductor.
 6. The electronic componentaccording to claim 5, wherein an opening is formed in a part of theinsulating film on the second conductor in which a surface of the secondconductor is exposed.
 7. The electronic component according to claim 6,further comprising a third conductor which is formed in the opening andis thicker than the second conductor.
 8. The electronic componentaccording to claim 7, wherein the third conductor is extended over theinsulating film.
 9. The electronic component according to claim 8,wherein the first conductor and the third conductor are formed indifferent layers.
 10. The electronic component according to claim 5,wherein a surface of the insulating film is flat.
 11. The electroniccomponent according to claim 5, wherein the insulating film is formed onalmost throughout a surface of the substrate.
 12. The electroniccomponent according to claim 11, further comprising: a fourth conductorwhich is formed in a same layer as the first conductor; and a fifthconductor which is faced to the fourth conductor through the insulatingfilm.
 13. The electronic component according to claim 5, wherein a filmthickness of the dielectric film is thinner than a film thickness of theinsulating film.
 14. The electronic component according to claim 5,wherein a dielectric constant of the dielectric film is higher or equalto a dielectric constant of the insulating film.
 15. An electroniccomponent comprising: a first conductor which is formed on a substrate;a dielectric film which is formed on the first conductor; a secondconductor which is formed on the dielectric film and thinner than thefirst conductor; and an inductor element having a coil conductor formedin one piece with the first conductor and formed in a same layer as thefirst conductor, wherein a capacitative element is configured of thefirst conductor, the second conductor and the dielectric film, thedielectric film is formed only on the first conductor, and an end partof the coil conductor functions as the first conductor and the inductorelement configures one of a resonant circuit and a filter circuit withthe capacitative element.
 16. A method of fabricating the electroniccomponent of claim 1, comprising the steps of: forming the firstconductor on the substrate; forming the dielectric film on the firstconductor; forming the second conductor which is thinner than the firstconductor on the dielectric film, wherein the capacitative element isconfigured of the first conductor, the second conductor and thedielectric film; forming an insulating film on the second conductor;forming an opening in the insulating film in which a surface of thesecond conductor is exposed; and forming a third conductor which isthicker than the second conductor in the opening.